[1] On the album, Cooper performs on a variety of percussion instruments, including African balaphone, bass drum, and sock cymbal.

In a review for AllMusic, Brian Olewnick wrote: "On Root Assumptions, with a balaphone (an African antecedent to the marimba) featured prominently, Cooper creates an amazing and beautiful variety of percussive sounds, rhythms, and melodies... making the session an unforgettable one.

His main source of inspiration appears to have been the West African percussive tradition and, possibly, the minimalism of Steve Reich, himself heavily influenced by Ghanaian drumming.

"[1] Nate Chinen, writing for The New York Times, described Cooper as "an alert, rigorously precise drummer who drew from a wide palette of textures," and noted that Root Assumptions "evoked both tribal music and minimalism.

"[4] A reviewer for New Age magazine wrote: "Using an African balaphone, a bass drum, and a sock cymbal, [Cooper] creates mysterious modern rituals which produce nice psychic effects for the attentive listener.