I've not heard a song by that name. However, in a historical context, "John Barleycorn," used as a metaphor for liquor and its evils and/or benefits, ranks right up there with "Red Eye," "Who Hit/Struck John," "Old Reliable," "Tongue Oil" and "Demon Rum" - not to forget the evergreen "Booze." Surely, there is a song containing the term, if not an actual eponymous hymn in praise of old "J.B".