When Charlie Parker and Dizzy Gillespie went into the recording studio together on 28 February 1945, they had already served a shared apprenticeship in the big bands of Earl Hines and Billy Eckstine, had jammed informally exploring their common interest in adventurous extensions of swing harmonies and reconfigured rhythms, and were, individually and collaboratively, prepared to redirect the course of modern jazz. That session shouldn’t in any way be considered the public “birth” of bebop; those seeds had already been sown by Dizzy in recordings with, respectively, Don Byas and Dexter Gordon. But the pairing of Parker and Gillespie at this time was to prove noteworthy for two circumstances – their bril- liance together, and (despite future recognition as the seemingly joined-at-the-hip father figures of bebop) the subsequent rarity of their appearances in partnership, facts that account for the importance of this collection of live performances.