 The first, known print appearance also occurred in 1939, but the term was little-used subsequently until applied to the music now associated with it in the mid-1940s.Thelonious Monk claims that the original title "Bip Bop" for his tune "52nd Street Theme", was the origin of the name bebop.Some researchers speculate that it was a term used by Charlie Christian because it sounded like something he hummed along with his playing.