In 1966, Bob Dylan with Blonde On Blonde and Frank Zappa with Freak Out created the pop music formula of the double album. Miles adopted it in 1969 with Bitches Brew, the first in a series of 10 releases in this format that were perfectly adapted to the trumpeter’s musical arrangements of this period. In 2001, the public was offered two entire unreleased sets of the second of two evening concerts (March 7, 1970) held at the Fillmore East. Miles made his stage entrance at this venue, which for three years had been New York’s temple of rock. The Brazilian percussionist Airto Moreira joined the quintet just as Wayne Shorter was making his final appearance. Using a discontinued phrasing that reflected a great rhythmic freedom, the saxophonist gave himself over to the rhythm created by Corea-Holland-DeJohnette, which verged on a musical abstraction that must have surprised the audience that had come to hear the Steve Miller Band and Neil Young’s Crazy Horse in the second half of the concert. In regard to this tendency toward abstraction, one might note that the program already included “Willie Nelson,” which the group had begun working on several days earlier for the future album Jack Johnson.