By 1935 there were four major transcription services supplying 350 radio stations: World Transcription Service, Standard Radio Library, RCA/NBC Thesaurus, and the C.P. MacGregor service. Each of these companies provided a basic library of radio shows complete in themselves except for local commercial tie-ins, a library of musical selections, a license to play them on the air, and periodic issues of new discs and replacements. These libraries did not "belong" to a radio station; they were leased for as long as station paid the necessary fees.
You're An Education
There's Honey On the Moon Tonight
C.P. "Chick" MacGregor was a prolific producer of music transcriptions and syndicated programming for radio. Among the discs his company distributed to subscribers for a period in the late 1930s was this series of 10-inch 78rpm discs with label credit to MacGregor as the primary artist
Electrical transcription audio courtesy of The Rick Colom Collection: There's Honey On The Moon Tonight (Coots-Gillespie-David) by "Chick" MacGregor and his Royal Highlanders (actual 78 label scan not available)
Isn't It Wonderful, Isn't It Swell (instrumental)
Silver on the Sage
You Go To My Head