Prior to his departure, Johnson played on all but two of the new album's tracks. His replacement was Jaco Pastorius, a virtuoso fretless bass guitarist from Florida, who had been in touch with Zawinul for several years, and who came in to play on "Cannon Ball" and his own composition "Barbary Coast". Zawinul and Shorter had assumed that Chester Thompson would be departing alongside his friend Johnson, and for the second set of sessions they replaced him (on Jaco Pastorius' recommendation) with the former Mahavishnu Orchestra drummer Narada Michael Walden. Although Walden played on several album tracks, he ultimately proved unsuitable. Thompson returned for the final "Black Market" sessions, but left again after failing to gel as a rhythm section with Pastorius (whose style was much busier than that of Johnson). Thompson subsequently joined Genesis as their touring drummer.