Group Ongaku has been played on NTS shows including Fractal Meat On A Spongy Bone, with Object first played on 2 November 2021.

グループ・音楽 Group Ongaku ("Music Group") was a collective exploring musical improvisation from 1958 through 1962. It was originally an improvisational duo between Skukou Mzuno and Takehisa Kosugi, who both were studying music at Tokyo National University of Fine Arts and Music. Later, between 1959 and 1960, the group expanded to include Mieko Shiomi, Yasunao Tone (both participants in Fluxus, along with Kosugi), Mikio Tojuma, Genichi Tsuge, and Yumiko Tanno. As a group, it would meet at various locations, such as Mizuno's house, and improvise together, using found objects, random instruments, tape machines, and radios. In addition, strategies were employed to expand the musical experience such as spontaneously responding to non-musical sounds with musical instruments, or consciously producing sound in relation to another's actions. Through such strategies, a heightened and spontaneous dialogue was created among the group. Such efforts can be understood as an attempt to collapse the point of composition onto the moment of performance.