<P> The song was first recorded on July 15, 1942 by Glenn Miller and His Orchestra at Victor Studios, Chicago, Illinois, in a Wednesday session that lasted from 11: 00 am to 3: 15 pm in one take . The 1942 lyrics to the song as recorded by Glenn Miller were: "It must be jelly' cause jam don't shake like that / It must be jelly' cause jam don't shake like that / Oh Mama, you're so big and fat!" </P> <P> The Glenn Miller civilian band played the same arrangement that was performed at least twice, available on a Victor 78 recording, Victor 20 - 1546 - A, recorded July 15, 1942 . There is also a version taken from a radio remote broadcast from September 15, 1942 in Boston, Massachusetts and later re-released by RCA Victor on LPT 6700 . </P> <P> "It Must Be Jelly (' Cause Jam Don't Shake Like That)" was the first song performed on the October 16, 1943 I Sustain the Wings radio program with the Army Air Force Band . </P> <P> The 78 single, Victor 20 - 1546, reached number twelve on the Billboard charts in January, 1944, where it stayed for eight weeks on the charts . Moreover, the record was a crossover hit, reaching number two on the Billboard' Harlem' Hit Parade Chart on February 19, 1944, the then equivalent of the later R&B chart, and number sixteen on the Billboard Juke Box Chart . </P>

Must be jelly cause jam don't shake like that meaning