Before teaming with the legendary arranger, trombonist and band leader Glenn Miller, MacGregor played with jazz musician, songwriter and recording artist Irving Aaronson.
Original 78 rpm Miller records such as In the Mood, Tuxedo Junction and A String of Pearls are mainstays of 1940s popular music and cultural collectors items representing "the greatest generation."
Actor Harry Morgan, a well known veteran of dozens of later television roles including December Bride, Dragnet and M*A*S*H, portrayed MacGregor in the 1953 Universal Pictures biography, The Glenn Miller Story.
[3] Chummy MacGregor also composed a series of songs with Charles Ives: "The Cage", "Berceuse", "Evidence", "Disclosure", "Down East", "Allegro", "The Camp Meeting", and "The Circus Band".
Herbie Mann, Hal McIntyre, Meredith D'Ambrosio, Gil Goldstein, Flavio Ambrosetti, Franz Koglmann, and Charlie Shoemake have also recorded the song.
"Moon Dreams" was also featured on the soundtrack collection Ken Burns Jazz: The Story of America's Music (2000), in a performance by Miles Davis, arranged by Gil Evans.