This pattern, "one of the most common vehicles for improvisation," forms the basis of countless (usually uptempo) jazz compositions and was popular with swing-era and bebop musicians. For example, it is the basis of "Shoeshine Boy" (Lester Young's 1936 breakout recording with Count Basie) and Duke Ellington's "Cotton Tail" as well as Charlie Christian's "Seven Come Eleven," Dizzy Gillespie's "Salt Peanuts," and Thelonious Monk's "Rhythm-a-Ning". The earliest known use of rhythm changes was by Sidney Bechet in his September 15, 1932 recording of "Shag" with his "New Orleans Feetwarmers" group.