PART 4 THE SWITCHBOARD

The crown jewel of the new Radio City Music Hall was the General Electric stage lighting switchboard, its dazzling amber, red, green and blue pilot lights burning like a perpetual Christmas tree, luring into show business all those who gazed upon it.

The first published photograph of the Music Hall board was a brain teaser-- where was the switchboard?  With 313 dimming controls, it was the latest "world's largest switchboard" and yet it was also the smallest.  With a height of 5'6", it was shorter than most people and only 15'6" wide.  This overhead shot was probably taken from D-Cove.

Claims to the "world's largest switchboard" dated back at least to 1925, the Chicago Uptown Theatre boasting its Frank Adam/Major switchboard was 28 feet wide.

The next year, 1926, the Los Angeles Al Malaikah Shrine Temple bragged that their 26 foot wide Hub board was the world's largest.  The wide spacing between dimming controls was necessary because huge lighting loads exceeded the capacity of the largest resistance dimmers, 3680 watts, and behind the blank plates, multiple dimmers were mechanically linked to a single control, in the case of the Shrine Temple, as many as five.

Since 1922, a partial solution to the switchboard width problem, in the form of a reactance dimmer, had been offered by leading resistance dimmer manufacturer Ward-Leonard.  To increase the density of the dimmers and eliminate the gaps, lamp loads in excess of 4000 watts were dimmed by newly-invented, remotely-located reactors, controlled from the stage board by small DC resistance plates, intermingled with standard AC dimmers for smaller loads.  Theatres equipped with reactance dimmers required both AC and DC street current, or alternatively, motor generator sets were used to supply the DC control voltage.  

Impresario Roxy took advantage of this invention and his 1927 Roxy Theatre Hub switchboard was "without question the largest stage switchboard that has ever been built" but was only 22 feet wide.  It weighed "over fifty tons" and required three operators, or "Magi's" as previously mentioned.

Three years later the last of the largest resistance plate boards was installed in the Hollywood Pantages, twenty-seven feet wide.

Even the most compact boards, such as the still extant 19'8" wide Atlanta Fox Theatre Hub board, occupied most of the wing.  With upper ventilation grilles for the resistance plates, the Fox board stood 12 feet high.

These large boards all featured "pre-selection" or "pre-sets," but only for switching, not dimming.  This subject has been fully covered in a previous photo essay titled "Secrets of Preset Pre-selective Switchboards" which can be seen here. 

Another difficulty with the large boards was that the interlocking feature did not allow for proportional mastering.  To precisely master four dimming controls set at varying intensities, for example, four hands were required.  

Similarly, the slow motion wheel installed on many large boards allowed for cross-fading among master dimmers, but only if the dimming controls were all "locked" at the same intensity.

The first switchboard to break the size barrier was installed at the new Chicago Civic Opera House in 1929 by General Electric (GE) and combined two of their recent inventions, whereby dimming was effected by their "thyratron" tube and the dimming control by their "selsyn."  This 140-dimmer, two-scene switchboard was the first to feature dimming presets and the first to be located so that the operator could see the stage. Already a primary source for light bulbs and motor-generators, GE's first entry into stage lighting control was the Chicago board, and the last to be completed before the stock market crash, which all but halted new construction. HD view.

This hybrid electro-mechanical machine remained in service for almost fifty years despite its Rube Goldberg approach to dimming.  From the only available technical description (reprinted verbatim in five trade magazines), it is unclear if proportional cross-fading was achieved.

The next documented electronic board appeared two years later in January, 1931 when Westinghouse installed in the Los Angeles Theatre their first electronic board, a sleek art deco 64-dimmer, five-scene machine with a slow motion wheel that resembled the speed control in a passenger elevator.  Westinghouse, already a leading stage switchboard manufacturer and chief competitor to GE, described their board as "thermionic" instead of "thyratron" which was a GE trade name. A detailed technical description of the board can be seen here.

This Los Angeles Theatre board (closeup, below) appears to have been the first to achieve fully electronic proportional fading, but according to the technical description, cross fading was sequential and did not allow fading from Scene One to Scene Three, for example.  To view additional photographs of this board in recent years may be seen at Bill Counter's excellent Los Angeles theatre site, click here.

In February, 1931, Westinghouse unveiled their next electronic model, which bore absolutely no resemblance to their Los Angeles installation of only the month before. Designed "in consultation" with stage lighting expert Stanley McCandless, the 36-dimmer, four-scene switchboard was constructed in the shape of an organ, complete with foot pedals, and installed upon the orchestra lift in Severance Hall, the new home of the Cleveland Orchestra. HD view.

Deceptively billed in the press as a "thermionic light organ" the board was expected to perform more like a Wurlitzer than a Westinghouse.  "This was the most ghastly thing imaginable," wrote conductor Sokoloff.  "A third rate movie house couldn't have devised a more vulgar effect."  The console was banished from the stage and a projection room remote served until 1958.  The device was electro-mechanical, as this view from the rear illustrates, filled with mechanically ganged potentiometers, magnetic clutches, and a sizable motor.  HD view.  The board also included a one-of-a-kind electro-mechanical system to patch its 110 branch circuits to the 36 dimmers and a joystick for aiming nine spotlights. 

Like the Los Angeles board, Cleveland's DC control voltage was supplied by generator, three in fact, as shown below.  A detailed technical description can be seen here. 

Westinghouse reverted to the Los Angeles model for their next switchboard, installed in early 1932.  Mounted backstage in the Long Beach (California) Municipal Auditorium, it featured 45 dimmers and a ten-scene preset.  No technical information is available, but high resolution photographs are, courtesy of Ron W. Mahan.  HD view.

What are likely the scene master faders are seen in the foreground on either side of the house phone.   HD view.

New York City received its first electronic board in August of 1931 in a pricey renovation of the Earl Carroll Theatre which also included rising microphones, program lights, and backstage paging.  Discarding their Chicago selsyn controls in favor of sliders, General Electric installed the 50 dimmer, two-scene board (described in some detail here) directly in front of the orchestra pit.  HD view. 

The controls were slide pots, as shown below, but there doesn't appear to be a cross-fader.  Within a six month period, probably in an effort to win the Radio City-RKO bid, GE installed similar (but smaller) thyratron boards in RKO houses in Schenectady and Albany, New York and in Denver.  According to the electrical specification, page 112, the Music Hall sought bids from GE, Westinghouse, and Hub. 

GE's linear control design was totally discarded for the Radio City board, its December, 1932  "glamour shot" shown below.  Among the remarkable design advancements included were cross-faders with precise position indicators; AC instead of DC control voltage which allowed for newly-invented inductor potentiometers, eliminating all moving and sliding commutating contacts; and the elimination of motor-generators as the source for DC control voltage.  With five scenes and 313 dimming controls, it was truly "the world's largest switchboard" and it was sexy.  HD view. 

30,000 radio sets could be operated off the electricity consumed by the Music Hall, claimed the only advance press description of the switchboard.  Unlike New York's Broadway theatres which operated on DC current, the Music Hall was the first newly-constructed Manhattan theatre to be supplied exclusively with AC, a fact which necessitated the installation of a bank of motor-generator sets to feed their arc lights, while thyratron vacuum tubes rectified the AC into DC for dimmer control voltage.

Perhaps the most important "first" achieved by the five-scene Music Hall board was that it could be-- and was-- operated by one man.  The large GE logo (upper left) was positioned for all to see.

The switchboard was designed and built at the GE Schenectady Works. 

Inspired by the surviving title page of the original operating manual, what follows is an operating tutorial.

To gain access to the switchboard, one took the prompt side (West 51st Street) passenger elevator or stairs down to the basement shop level and proceeded to the crossover (A); then downstage past the footlight motor access corridor to the curved orchestra pit hallway (B); and then to the Electrical equipment room (C).  Entering the room, one flipped two light switches:  one for the equipment room and for the switchboard running lights.  One then climbed the ladder up through a hatch to the switchboard location on the floor above.

The D-cove view of the switchboard revealed (1) the white stage dimming controls, (2) the color-changer panel, (3) the masters, (4) the colored stage dimming controls, and (5) the dimming controls for the house lights.

The console controls were laid out in an entirely novel way, split into four quadrants divided horizontally by a control bench.  In the near foreground are the 64 white dimming controls for the independent stage floods, and above them the controls for the stage side bridges and towers.  Seen in this dress rehearsal photo are head switchboard operator Andy Herzog and head electrician Eugene Braun, both former 1927 Roxy employees who opened the Music Hall and remained there for 35 years.  Mr. Herzog is working two controls in the colored stage section and at his knee level are the controls for the house lights.  Mr. Braun is taking direction from Roxy's box over the Dictograph intercom, utilized for rehearsals only.  There were a total of 4,400 operating handle on the Music Hall board.  HD view. 

The upper left white quadrant contained the 72 dimming controls for the stage side bridges and towers, arranged in four groups with master controls to the right of each group.  The top row corresponded to Entrance 1, the second row Entrance 2, and so forth.  Every dimmer control on the board was part of some group, and there were 39 groups all told.  Color photographs of the switchboard are from the author's personal collection.  HD view. 

Here is a typical nameplate, for a group master, far left, second row, "P. E. 2" meaning prompt side, entrance 2.

From left to right, the top right quadrant contained the 72 colored controls for the footlights, stage borderlights, cyc foots, and floor pockets.  There  were six controls for the floor pockets in each color, pockets 1 through 4 PS and OP and rear pockets, P & OP.  Miscellaneous dimming controls on the far right included the stray fifth color circuit in the footlights (white) and the stray fifth color circuit in the K1 and K2 cyc borders (daylight blue).  Other faders controlled floor pockets installed in the four elevators and turntable, stage chandeliers, organ and choral spots, music stand lights, and the cyclorama stars.  HD view. 

The lower right quadrant ("knee dimmers") contained the 68 colored house light and ten miscellaneous white controls.  

The first step in operation was to turn on the switch marked Control Power at the far right end of the house light controls. 

The next step was to turn on the eight Filament switches, also located on the lower section of the board, namely Masters, Borders, Floods, Towers, Pockets, Bridges, Foots, and House lights.  After that, one consulted the clock, because the board required a ten minute warm up, a splendid opportunity to smoke one, or even two, cigarettes.

The red, blue, and amber lights above the clock were cue lights, which along with the ever-present buzzer, signified Panic, Projection, and Stage Manager, respectively.  To the left and right of center were buzzer keys for stage manager and nine arc light positions, identified below.

Suppose one wanted to energize the green footlights.

First, crank the Grand Master to -10- because all faders are under the control of the Grand Master.  The Grand Masters for both the Stage and House could be found at the center of the board, flanked on either side by the Stage and House Scene Masters.  

Next, locate the dimming control for the green footlights.  Since the footlights were rehearsal letter "A," the control is first in the row of colored stage dimming controls (circle), to the right of the central controls and the Stage Green Master.  

There were four different ways to activate a given dimming control.  The simplest and most direct was to set the selector switch to "unit" and "Bring up the green footlights in unit," meaning independent.  Raising the large unit fader even the slightest bit would activate an integral power switch and in response, the footlight dimmer assembly, located in the basement reactor room, would energize the green pilot light to the left of the fader. 

Raise the unit fader to the desired intensity and voila!-- green footlights.

Perhaps the operator wanted the green footlights to be under the control of the adjacent Stage Green Master, circled, which was its group master.  

By flipping the unit selector switch to Group, and the selector on the Stage Green Master to Master, the Stage Green Master fell under the control of the Stage Rehearsal Master, which in turn was under the control of the Stage Grand Master.

If the Stage Green Master was switched to Group, the group fell directly under the control of the Stage Grand Master.

If the dimming control for the green footlights was switched to Pre-set, the unit fader was disabled and the five preset faders engaged,  The preset faders could be assigned either to Scene Master or Supplementary Master via the toggle switch above it.  Starting from the left, the first fader was for scene one, the next for scene two, and so forth and fell under the control of its respective Scene Master fader.  Below left, the scene one green footlights fader, at fifty percent, is assigned to supplementary scene one, top left in the right hand photo.

All ten of the Stage Scene and Supplementary masters were under the control of the Stage Grand Master.   "Group" was the normal operating position; "master" slaved the supplementary and scene masters together.  HD view. 

The combined output (Scene plus Supplemental) of Scene One, for instance, could then be assigned by "preset switch" (below, center left) to either the A or B side of the stage Cross Fader control. The clock indicator for the stage cross fader (bottom left) shows the B side to be hot.  With the green footlights in scene one, flipping the scene one preset switch down on the B side would make them hot, and if no scene was selected on the A side, "clocking" (cranking) the stage cross fader to the A side would fade them out.  A given scene could be assigned to either the A or B side, but not both by virtue of an electrical interlock in the multi-pole basement relays.  HD view. 

All six of the faders in a typical dimming control unit were mechanically connected by tiny woven bronze cables through a series of pulleys to the piston of a small reactor, also termed a "solenoid potentiometer" or "inductor."  Raising the inductor control from -0- would first trip an integral power switch, then increase the 0 to 180 AC voltage sent to, in this case, the green footlight tube panel in the basement reactor room.  There it was converted to 0 to 20 volts DC, so to control the dimmer, a large saturable core reactor.  The output of the dimmer was in turn connected to the branch circuits of the green footlights via its distribution panel.  Faders could be "trimmed" mechanically by adjustment to the fader handle shaft.  Although the term was not yet in use in 1932, each of the unit controls were plug-in "modules" and could be easily removed from the board for maintenance.  HD view. 

Below in a diagrammatic riser section can be seen (1) the stage switchboard, (2) the attic reactor room, and (3) the basement reactor room.  The attic reactor room ran the full width of the building from 50th to 51st Street, and the basement room ran almost the full sixty-six foot depth of the stage.  Stage-bound circuits, such as floor pockets and footlights went downstairs; overhead stage lighting and house lights went up.  HD view. 

The thyratron tube panel, saturable core reactor dimmer, and distribution panel were incorporated into one assembly whose face looked like this. 

The backside of the tube panel looked like this.  HD view. 

Below, a view of the tube panels in the reactor rooms, basement (left) and attic (right) where the thyratron and phanotron tubes cast an eerie blue glow.  All told, there were over 1600 of these fragile vacuum tubes in the reactor rooms and "failure of a tube from any cause resulted only in the corresponding circuit lamps being extinguished."  HD view. 

One hundred seventy-eight reactor assemblies were housed in the attic reactor room, within four racks, one of the shown below.  To the left is a photo of the saturable cores located directly behind the tube panel.  The three enclosed devices (center right) contained the emergency throw-over contactors which automatically brought the amber house lights to full bright, powered by the sub-basement emergency generator, in the rare case of a power failure.  HD view.

On the backside of the racks were the distribution panels, containing the dimmer's holding contactor (left), which operated on DC to avoid the hum and chatter associated with AC relays.  The majority of the three hundred and twenty-eight dimmers were 2000 watts, with a single branch circuit fuse, and the largest were 16,000 watts for the heaviest loads such as K Border (cyclorama) and the eight house light coves, with multiple branch circuit fuses (right).

A simplified drawing illustrated the relationship between the dimming control inductor (top left) and its associated dimmer.  

The twenty scene masters and rehearsal and grand master switchboard controls for both stage and house were also associated with reactors, located in the basement, as illustrated below.  The exceptions were the 39 group masters, whose control handles were mechanically linked to autotransformers located with the console.

The selsyn section of the switchboard, separate from the dimming function, was devoted to color-changing and arc light dousing, the two controls panels shown below in blue.

On the far left of the console desk was the main selsyn control panel, divided horizontally into four banks, one for each color.  The colors were not necessarily amber, red, green and blue, but rather whatever gel was loaded into the frames of any of the 120 plano-convex spotlights (floods) or the eight "boomerangs" associated with the musician's or orchestra floods in C-cove, the O's and X's.

Below, a closeup of the left portion of the main control panel.  There were twenty-one controls, from left to right, Boomerangs, Proscenium Floods (rehearsal letter B), Bridge C Floods, Portal Floods, Bridges E-H Floods, and Side Bridges P & OP 1-5.  For some reason the towers, also equipped with selsyn color changers, were omitted.  HD view. 

On the far right of the panel were the four master controls, one for each color row, the lower two show below.  There was also a single master key marked Forward and Reverse.

Each of the four horizontal color row were associated with 6 and 8 cycle 25 volt DC motor-generator sets and the starting controls were located center, in the lower part of the console.  To the left and right of the starter switches were master speed controls for each of the four colors and above them (and unrelated to the selsyn function) were the worklight controls, separate on and off push buttons for the worklights contained within each of the eight borderlights.  HD view. 

The 120 individual selsyn color changers, model number 2JD123A1 (left) were manufactured by GE for Kliegl Brothers, under a contract separate from the switchboard, requisition number N-523055.  On the right is one of the 91 selsyn transmitters, located in the electrical equipment room in the basement beneath the switchboard.  HD view.

To the right of the house light masters on the console desk was the selsyn control for the carbon arc front and bridge light blackout dousers, with control divided into eight groups:  Stage P & OP (bridges); Proscenium P & OP; D-Cove; Kino booth; and Spotting booths, P and OP.  All told there were 548 selsyn receivers, 480 for the 120 floods, 32 for the boomerangs, and 36 for the carbon arc lamps.  HD view.

Below, a grainy view of the switchboard under construction showing the three selsyn components.  HD view.

Behind the switchboard, and invisible to the audience on the downstage wall of the orchestra pit, were eight removable access doors for maintenance.  Below, apprentice electrician Eric Titcomb in 1979 at the rear of  the board and standing on the orchestra pit elevator, lowered a foot below the switchboard.

During performances, one operator ran the switchboard, with an 8-4 two-show morning man, a 4-closing man, and a swing operator one day a week, according to Bob Lachenauer, shown below in an early 1960's publicity pose with head operator Herzog, who was present for all shows and attended to any emergency repairs required.  Bob recalls, "I would receive a pre-light plot and make a rough layout of how I would set up the board for the entire show.  I usually set the main opening lighting on a scene master and used its sup master to add additional lighting.  Often this wasn't possible, so you added a group master or individual unit moves.  At the 4AM lighting rehearsal on opening day, for about three hours we would alter the lighting I had preset, and at 7AM we started dress rehearsal and continued to alter the look of the show, now with the producer, Leonidoff or whoever.  We ran the shows visually by sight cues and occasional buzz cues from the stage manager.  We never wore a headset during shows."  HD view.

There were three house light settings: for walk-in, amber in one house scene master, which included the eight ceiling coves, the perforations or grilles, the orchestra side arches, the three mezzanine soffits, and the urns on the rear wall of the third mezzanine. For the stage shows, blue soffits and urns in scene two master, and for the movies, the amber soffits and urns in scene five.  HD view.

The red and green house lights were reserved for special occasions.  "For the Easter dawn service," recalls Bob Lachenauer, "I brought up one of the unused house masters to full intensity, then sat on the floor of the board at the house light controls.  I usually used all of the cove lights in the unit position and starting with the H Cove Blue, I slowly raised its intensity to full.  Before I got it to full, I had already started raising the intensity on G Cove to full. I did this for all coves, and as I finished with the A Cove (closest to the stage) I started to add the H Cove in Green.  I continued this with the Red and Amber Coves until all colors were lit.  I then just flipped all 32 selector switches to preset, tying them into the house master I had selected."  Below, the house light controls and the brass foot rail.

To the right of the house light controls was the throwover panel, also called "extended control."  Inserting an insulated pin into any of the sockets would throw the guarded emergency house light push button into the circuit, located on the backstage Peter Clark Stage Manger Control Panel.  As part of standard procedure, the pin was inserted into House Scene One, the socket marked in yellow, below.  HD view.

Below, circled, is the backstage push button, the "enabled" pilot light, and the pilot light lamp test button.  Recalls Bob Lachenauer, "when the organ breaks were over preceding the show or movie, using the house master fader, I would cross fade from one scene master to 5 scene master. At that point we inserted the throwover pin and then cross faded back to the one scene master. The lights in the one scene master would bump on if the emergency switch on the stage control board was thrown or I pulled the pin on the board."

Improvements were made to the switchboard over the years, the most visible being alterations to the preset selector section.  The original scene selector and the 1943 version flanked the filament switches, which by 1960 had moved to the lower part of the board, replaced by scene intensity voltmeters.

The switchboard was built in the Schenectady works of Thomas Edison's General Electric Company, a vast plant employing thousands.

The switchboard "was designed by E.D. Schneider of the General Electric Company in cooperation with Eugene Braun who designed the stage lighting installation," claimed Lyman Brenneman in his 1999 article. Yet there is no corroborating evidence to support this assertion, and more likely the board was the result of a collaborative effort.   As shown below, left to right, Chauncey Suits and Dudley Chamber were the inventors of inductor fader patented by GE; Albert Wallace Hull developed the thyratron; and the names of Harry Palmer and Dudley Chambers appear on the Music Hall schematics along with that of Mr. Schneider.

Elbert Schneider was the author of "Thyratron Reactor Lighting Control" (1938) in Transactions of the AIEE which can be read here, but it is Dudley Chambers' name which is found on the Elementary Wiring Diagram, below.  This schematic reveals the terrific complexity of circuits involved in energizing the green footlights, circuit #50 on the drawing.  HD view.

In interpreting the above, it may be helpful to know that this is the symbol for capacitor:

Other possible contributors to the design of the board could have been Rapp & Rapp, consulting architects for RKO, whose representative annotated (and preserved) the electrical specification and Edward Silverman, electrical engineer for Clyde R. Place. Clyde R. Place, consulting engineer for all of the Rockefeller Center Development, was a highly-respected engineer whose works included Grand Central Station and the prestigious Taft School, their 1930 34-dimmer Westinghouse board shown below.

But what of Eugene Braun's contribution? "Mr. Braun designed the lighting for both the stage and auditorium of the Hall" read his obituary in the New York Times, and Variety related in 1932 that "Roxy placed Eugene Braun in the Engineering Department during the construction of the building." Below, far left, Braun accepts a bowling trophy won by three of his front light operators.

"Mr. Braun had a great reputation in the industry and he was very well liked," recalls switchboard operator Bob Lachenauer, hired by Braun in 1959.  Eugene Braun's opening night billing was "Electrical Engineer" but by 1937 his title had become "Stage Lighting Director."  In fact, he was the head IATSE electrician and he was also a highly-regarded special effects man, most frequently billed in the programs as "Lighting Effects by."  "I don't think up these ideas," says Braun in the article below.  "That's up to the show producer."  The occasion was his 1959 burning of Nome, described by Variety as "such an authentic simulation of an actual fire, complete with flames, smoke, and crumbling buildings, that the sight is truly awesome."  

Prior to his Music Hall career, while Braun was electrical supervisor at the 1927 Roxy Theatre, he was lent out by Roxy "in an advisory capacity" to superintend the stage lighting installations in four of the five super-deluxe Fox Theatres, namely Detroit, St. Louis, Brooklyn and Atlanta.  Below, the Atlanta switchboard, with 184 dimmers and 120 dimmer controls.

Braun was also the electrical engineer at the RKO Roxy (Center) Theatre, originally equipped with an electronic Hub switchboard with 190 dimmers, replaced in 1934 with a Westinghouse five-scene board with 181, shown below.  The completely new design of this board, which utilized the newly-perfected Ward-Leonard "Hysterset" dimmers, seems to imply that the dimming and control technology employed in the Westinghouse Los Angeles and Long Beach installations did not meet Braun's specifications.  A detailed technical description of the board can be seen here.  Evidence suggests that this was the last stage switchboard manufactured by Westinghouse.  HD view. 

The 1934 GE switchboard at the old Metropolitan Opera was a scaled down version of the Music Hall board with half the number of dimming controls (156), only three scenes, and a newly-designed inductor dimming control.  Not until "A Chorus Line" forty years later would another electronic board be utilized on Broadway.  Technical descriptions of the Met board can be seen here and here.  HD view.

In 1957, the last advertisement linking Kliegl Brothers and the Music Hall ran in the trades, making the claim that "all of the original lighting and lighting control equipment we installed in the Music Hall. . . is still in active everyday use."


In the early 1960's, head electrician Eugene Braun approached several vendors to obtain quotes for the replacement of the GE stage switchboard.  According to Richard D. Thompson, sales engineer for Ward-Leonard, "I found to my surprise that the control technology of the original system surpassed the design concept we were promoting at the time. . . and to duplicate the existing capability. . . we could no longer house the [proposed] control console in the existing space in front of the orchestra pit."  Plans for a new switchboard were abandoned.  Below, a twenty-dimmer, five-scene preset Ward-Leonard board from 1960, with no room for the remaining 293 dimming controls the Music Hall required.

Sometime after the introduction of quartz lighting instruments in 1964, the plano-convex stage floods were replaced with Kliegl lekos and, with the exception of C-cove, the selsyn color changers were abandoned.  In this undated photo, an 8" Kliegl quartz leko can be seen hanging above the Rockettes concealing the Peter Clark fly rail.

Head electrician Billy B. Walker posed between a leko, a fresnel, and a walkie-talkie, none of which had been invented when the Music Hall opened in 1932. 

In 1974, seventy-seven-year-old Leon Leonidoff retired, the last of the old guard to go.  In 1979, the Hall ceased showing movies and stage shows as a regular attraction. 

In 1974 the Music Hall converted all the front lights from carbon arc to HMI, an arc light within a light bulb.  In 1998, the FR-10's were retired, but eleven of the Kliegl front lights remained in service through 2022, ninety years after installation.

In 1998, the switchboard was forced to retire, following the sixty-sixth Christmas show and after sixty-six years of almost daily usage.  The console remains permanently enshrined in the first row.

The five-color, motorized disappearing footlights remain intact.


The End.

###

Thanks.
Special thanks to Bill Counter and Garry Motter for their expert technical assistance.

Peter Balestrieri (University of Iowa), Mary Lou Barber, Laura Beane (Kennesaw State University), Michele Beckerman (Rockefeller Archive Center), Ken Billington, Lyman Brenneman, Liz Brock, John Calhoun (New York Public Library), Bill Counter (LA Theatres),  Rick Docen (Impact of Brass), Robert Endres, Dave Fedack, Bran Ferren, Rary Foreman, Stefan Grabener, Ben Hall, Thomas Hauerslev, Janice Herbert (Dancers over Forty), Brad Hohle, Mike Hume (Historic Theatre Photography), Dean Irwin, Diane Jaust, Dalton Kurrle (Kennesaw Blueprint), Bob Lachenauer, Scotty Lachenauer, Richard Logothetis, Judith Anne Love, Duncan MacKenzie, Thomas J. Mathiesen, John McCall, Joe Mobilia, Dana Mortensen, Jr., Garry Motter, Mrs. Puva (IATSE International), Ann Murphy, David Naylor, Rosemary Novellino-Mearns, Daniel Okrent, Ken Roe, Christine Roussel (Rockefeller Center Archive), Joel Rubin, Bill Savoy, Patrick Seymour, Doug Smith (Impact of Brass), Paulene Spika, Tony Tauber, Leith ter Muelen, Eric Titcomb, Bill Unotti, and Michael Zande.

December, 2023

For Further Reading.

Backstage at Radio City Music Hall 1932-- Peter Clark
The Motion Picture Daily Music Hall anniversary issues are loaded with facts and photos.
5th Anniversary, 1937
15th Anniversary, 1947
20th Anniversary, 1952
25th Anniversary, 1957

Radio City Music Hall, Kliegl Brochure, 1933.

Radio City Music Hall, Sound Equipment, SMPE Journal, 1933.

Radio City Music Hall, Projection, Selected articles.

Backstage at Radio City Music Hall, Dean Irwin.

The Brenograph, Thomas J, Mathiesen.

"Electronic Tube Control for Theatre Lighting,"SMPE Journal, March, 1935.   (RKO Roxy a/k/a Center Theatre)

"Thyratron Reactor Theatre Lighting Control," SMPE Journal, July 1936. (Metropolitan Opera GE board). 

"Thyratron Reactor lighting control enters movie theatre field," Projection Engineering, November, 1931. (Earl Carroll, RKOs in Denver, Schenectady and Albany.)

"New Theatre Light Control System," Projection Engineering, November, 1929.  (Chicago Civic Opera House).

"Playing Light on a Thermionic Organ," Motion Picture Herald, 9/26/1931.  (Cleveland Severance Hall).

"Technical Aspects of Modern Design," Motion Picture Herald, 10/24/1931.  (Earl Carroll Theatre)

"Thermionic Tube Control of Theatre Lighting," SMPE Transactions, January, 1932.  (Los Angeles Theatre). 

Bibliography.
12/20/1903, British Fire Prevention Committee, "The Fire at the Iroquois Theatre, Chicago."
1916, Arthur Edwin Krows, "Play Production in America."
1922, F.H. Richardson, "Richardson's Book of Projection."
1927, R.W. Sexton, American Theatres of Today."
1930, Louis Hartmann, "Theatre Lighting."
11/1932, Theatre Arts, "Building Number 10."
12/20/1932, Variety, "Stage Lighting: Radio City Music Hall."
1936 "Radio City Music Hall Quarterly."
1937-1974 "Radio City Music Hall Pictorial."
12/2/1940, Life magazine, "Rockette No. 33"
1/1941, Popular Mechanics, "Secrets of the Magic Theatre."
4/26/1943, Life magazine, "Radio City Music Hall."
1946, William Peck Banning, "Commercial Broadcasting Pioneer."
4/1949, Coronet, "Maestro of the Music Hall."
1949, Harold Burris-Meyers, "Theatres and Auditoriums."
4/1950, Popular Mechanics, "Hall of a Thousand Illusions."
1954, John Kenneth Galbraith, "The Great Crash 1929."
1955, Joseph Vasconcellos catalog (successor to Peter Clark).
1961, Ben Hall, "The Best Remaining Seats."
12/11/1964, Life magazine, "The Rockettes."
10/1974, Theater Crafts, ""Radio City."
1979, Charles Francisco, "The Radio City Music Hall."
1979, David Naylor, "American Picture Palaces."
1980, Judith Anne Love, "Thirty Thousand Kicks."
1991, Nicholas Van Hoogstraten, "Lost Broadway Theatres."
4/2001, Preservation News, "Backstage at Radio City."
2003, Daniel Okrent, "Great Fortune."
2012, Ross Melnick, "American Showman." (Roxy)
2014, Rosemary Novellino-Mearns, "Saving Radio City Music Hall."
2015, Ann Murphy, "How I Got My Kicks."
2017, Thomas Blalock, IEEE Power & Energy, "Reactors at the Roxy."
2023, "Lantern" website
2023, newspapers.com website
2023 Cinema Treasures website

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