I'm not sure the Louis Armstrong song is particularly well known. It seems like other artists had higher charting versions of the song at the time and it doesn't seem to be on the "Best Of" albums of his I looked up. It seems like the song is only somewhat known because it was the B-side to Armstrong's most popular single. Anyway, I think the clue would be stronger if you just didn't mention Armstrong at all. Maybe just say that Liza Minelli sang it in the musical?