He is most famous for his recording of the song "The Little Drummer Boy" (Carol of the Drum) written in 1941 and first recorded by the Jack Halloran Singers. However, Halloran's recording, made in 1957, was not released in time for that year's Christmas season. The song first appeared on records in 1958 and it was that version, recorded by the Harry Simeone Chorale, which became an instant classic. It was first released as a single, then featured on an LP entitled "Sing We Now of Christmas - The Harry Simeone Chorale", which went on to become the biggest selling choral LP of Christmas music ever, even outselling choral master Robert Shaw's memorable Christmas offerings. It stayed in the Top 40 for four years, from 1958 to 1962 - a near-impossibility for a choral Christmas album today. In 1963, it was re-released as "The Little Drummer Boy - The Harry Simeone Chorale", and has never gone out of print, although it has appeared at different times on different labels. It is Mr. Simeone's only album currently in print.