NBC broadcast this abridged production of Pirates, on June 20, 1939, from 8:30-9:25 p.m. The medium itself made its United States public debut that same year, at the New York World's Fair, so this must have been one of the first operas ever shown on American television. (The BBC broadcast operas as early as a Tristan und Isolde in 1937.)

Dave Kehs pointed out a passage in William Hawes American Television Drama: The Experimental Years (University of Alabama Press), which describes how it came about:

The third kind of musical was a delightful version of The Pirates of Penzance, by Gilbert and Sullivan. To assist director Thomas L. Riley, two light-opera experts were called in: Harold Sanford, who supervised the music; and Ivy Scott, who worked with dialog, movement, and detailed stage action.

Director Riley remarked: 'Among the techniques learned were the fact that in television a much smaller cast and orchestra could be used than is required on the stage. The script and score were cut closely making the plot completely coherent but with very little repetition thereby maintaining the rapid pace essential to good television.' After a few days of dry rehearsals, the cast was on camera for two days. A commentator was used to describe the scene as well as the cast and provide other program information during the intermission. Two scenes were required, one showing the exterior of a castle.

Later that same year, the same team produced Cox and Box and H.M.S. Pinafore, so the Pirates must have been judged a success. Unfortunately, we're not likely ever to see a copy these productions. As Charles Schlotter observes:

It is highly unlikely that any video or audio of the 1939 broadcasts now survives. TV was so experimental in 1939 that kinescope had not yet been invented. A handful of newsreels were filmed at early TV sessions, and somebody shot a home movie off the television screen that preserves a few moments of an early American broadcast. (I have now conveniently forgotten what it was, but recall that a very young Norman Lloyd was in it, and the Museum of Radio and TV has it. Not G&S, I know that much.) That footage was without sound, BTW. [IMDB details are here; hat tip Steve Dhuey. —ed.]

Unless somebody is sitting on a hidden collection of proto-kinescopes, the best we can hope for is that the TV signal might miraculously bounce off a distant planet and return to us.

Incidentally, the Frederic, Ray Heatherton, did a kid's program on WOR-TV (Channel 9, in NYC) called "The Merry Mailman" in about 1953 (per Bruce Miller and Charles Schlotter). He was the father of Joey Heatherton.