When the first continuing series of radio dramas was produced at WGY in 1922-23, there does not seem to have been any musical accompaniment. While no recordings exist to document this early series, none of the articles that I've found discussing the work of the WGY Players makes mention of musicians.
However, by the late twenties, musical scores had become a regular feature of dramatic programs -- and not just pipe organ accompaniment, either. Full orchestrations were in use from very early in the evolution of network radio drama. Even "Amos 'n' Andy," for their first three or four years on NBC, were introduced by a full orchestral arrangement of "The Perfect Song," arranged and conducted by NBC-Chicago musical director Joseph Gallichio. (The more familiar organ theme, first played by Dean Fossler, and later by Gaylord Carter, wasn't used until 1933 or so.) The song, taken from Joseph C. Breill's score for the film "Birth Of A Nation," was used only as opening and closing music -- but its sentimental, yearning quality nonetheless contributed greatly to the dramatic texture of the program.
An important figure in the development of dramatic scoring for radio was NBC's first musical director, Ernest LaPrade, who conducted the orchestra on the "Collier's Hour" and did many other musical tasks around the network as well -- he even apparently had a hand in the creation of the NBC chimes. Under his direction, scoring for radio quickly became a specialized art form.
The earliest surviving examples of network radio drama are several episodes of the Great Northern Railroad's "Empire Builders" series from NBC Blue, dating to late 1930 and early 1931. These Chicago-produced shows use music most expressively, beginning with the opening theme: elaborate live sound effects are combined with original music which cleverly produces the vivid impression of a churning locomotive. The fully-orchestrated music is used thruout the programs to point up emotion and to smooth transitions between scenes. In no way is it crude or primitive. The scores are quite complex -- there are quotes from classical pieces, interpolations of popular tunes of the day, and many original themes. In some ways, the technique is rather reminiscent of the synchronized music scores used in late silent films, although of course for radio, the music doesn't form a constant backdrop to the action.
Music is also used quite effectively in the original run of "Sherlock Holmes," an NBC-Blue feature from 1930-36. A surviving episode from January 1933 features an appropriately mysterious music score, filled with menacing stings that help to create the image of fog-bound London streets. While occasionally a bit shrill, the score still makes an important contribution to the drama.
Not all dramatic programs of the early 1930s used music -- consider the "Eno Crime Clues" series, another NBC Blue feature which also had a simultaneous run in syndication. These shows used no music -- instead, a gong was struck to open and close the episodes, and dead fades were used between scenes. The result is a show with a rather claustrophobic feel -- much deader than the Holmes example given above. Even this early, it was becoming apparent that music, used correctly, could be very important to the texture of a dramatic presentation.
By the end of the thirties, scoring for radio drama had become even
more refined, with the arrival of such masters as Bernard Herrmann 
at
CBS. Herrmann, a Julliard graduate, did his first known radio work in 1934,
scoring a David Ross reading of the John Keats poem "La Belle Dame Sans
Merci" for Johnny Green's musical anthology program "In The Modern Manner."
Herrmann scored four more poems that would be read by Ross on subsequent
programs in this series over the next year, and in 1936 moved into scoring
for full drama, on the experimental "Columbia Workshop."
It was on the Workshop that Herrmann made a name for himself as radio's most innovative composer. He was the Workshop's composer in residence for the entire 1936-37 season, and his works over that time span ran the gamut -- accompanying the heavy drama of "Macbeth" as well as the whimsical fantasy of "Mr. Sycamore." In this wistful story of a tired postman who decides one spring day to turn himself into a tree, Herrmann's delicate themes combined perfectly with the New England matter-of-factness of Parker Fennelly in the title role to produce a radio classic.
A week after "Mr. Sycamore," on April 11, 1937, Herrmann presented his impressive score for Archibald MacLeish's terrifying parable of totalitarianism, "The Fall Of The City." This production was the most provocative of the Workshop's initial season, and generated widespread critical acclaim. Herrmann's work drew its share of the plaudits, and it became obvious that big things were ahead for this bespectacled young man.
It was during the Workshop's 1937 production of "Macbeth that Herrman became associated with another yourg innovator, Orson Welles -- and their collaboration on the "Mercury Theatre on the Air" in 1938" is often considered radio drama's finest hour. Herrmann continued with the Mercury program's entire series -- as well as its successor, the Campbell Playhouse. In 1941, he accompanied Welles to Hollywood, where he soon established himself as one of filmdom's most provocative composers.
But he continued to contribute scores to CBS productions even after the move West. His scoring adds immeasurably to the works of Norman Corwin -- his compositions for "On A Note Of Triumph" (1945) are a perfect counterpoint to Corwin's poetry. Herrmann scores also enriched many of the early programs from the long-running "Suspense" series, notably "The Hitch-Hiker," a memorable Orson Welles outing from 1942 with a script by his wife, Lucille Fletcher. Even into the 1950s, Herrmann would return to radio for special productions -- his score for the CBS Radio Workshop's 1956 production of "Brave New World" is one of the most elaborate ever devised for a radio drama.
While Herrmann was venturing into new and experimental territories in his Columbia Workshop and Mercury Theatre scores, other composers were giving their radio scores a more traditional sound. One of the foremost of these was Louis Silvers. A pioneer in scoring for talking pictures -- he had been the first musical director for Vitaphone in the late twenties -- Silvers gave his scores for the "Lux Radio Theatre" a lush Hollywood quality -- lush, that is , without being overwhelming. Composers quickly learned that the larger-than-life sound of many film scores was simply too obtrusive for the more intimate medium of radio.
Live, original scores would remain an important part of radio drama until cost-cutting forced changes. Some shows, particularly sustainers, used organ scores as a way of preserving the value of live music without the expense of an orchestra. And, of course, for some types of programs, a lone organ is a far more effective background. "Inner Sanctum" wouldn't have been the same with an orchestra sawing away as Raymond drooled out his weekly greeting. A few shows omitted music entirely -- Arch Oboler, for one, often avoided musical scores in his productions, and the silent transitions do much to give his plays a dark, moody feel.
As radio wound down in the 1950s, stock music began to take over -- but even well into that decade there was some impressive work being done in scoring for drama. Rex Koury's original compositions for "Gunsmoke" were among the best dramatic scores ever done for radio. And even canned themes from music libraries could be effective if carefully chosen: the "Johnny Dollar" scores of the late fifties, though patched together from stock, can still be very evocative. On the other hand, the stock music could be distractingly poor: look up a late 50s CBS series called "Indictment!" for the proof. And, most of the stock scores used in NBC's "X Minus One" tend to give the episodes a corny, dated, late-fifties sound -- unfortunate for such an otherwise excellent "futuristic" series.
Stock music has remained the norm for most of the attempted revivals of radio drama -- an examination of CBS Radio Mystery Theatre will reveal mixed results so far as the music is concerned. As is typical of the series in general, a few of the scores are excellent, some are excruciatingly bad, and most are just "there" -- not interfering with the story, but not doing much to contribute to it, either.
Perhaps as interest in radio drama continues to build, there'll be a revival of interest in original scoring as well. After all, it'd be sad to see an art which was once so advanced disappear completely.
Text copyright by Elizabeth McLeod