Conversation so far:
what was Jikken Kobo?
an artistic group established for multidisciplinary collaboration on mixed-media projects, who sought to avoid Japanese artistic tradition.
what kind of projects did they produce?
During this period he wrote Saegirarenai Kyusoku I ("Uninterrupted Rest I", 1952: a piano work, without a regular rhythmic pulse or barlines).

Question: what else did he produce?
Self-contained rewrite: Besides Saegirarenai Kyusoku I, what else did Tōru Takemitsu produce?