Complex sentence: He spent much of the remainder of the 1970's as freelance session drummer, which a session with singer Kevin Ayres that also included future Police guitarist Andy Summers, and reunited with Charlie Whitney in the short-lived band Axis Point.
Split into simpler sentences: He spent much of the remainder of the 1970s as freelance session drummer. This time included a time with singer Kevin Ayres, and future The Police guitarist Andy Summers, and the reunited Charlie Whitney in the short-lived band Axis Point.