Collaborations are not uncommon in Merzbow's prolific catalog (over 400 releases and counting). But it is rare when he records as Masami Akita, his given name. Less than a dozen of his albums have been credited this way. Kouen Kyoudai, co-billed to Japanese composer, songwriter, and multi-instrumentalist Eiko Ishibashi, has that distinction. Ishibashi made a name for herself in the 2010s with two recordings on Drag City that showcase the quirky avant-pop singer/songwriter aspect of her musical persona, but it's wrong to try to put her in that box. She is a brilliant pianist, equally adept at free improvisation, modern composition, and jazz. She is also an inventive, commanding drummer and flutist. Ishibashi has collaborated with Tatsuya Yoshida, Keiji Haino, Akira Sakata, Oren Ambarchi, and Jim O'Rourke, to name a few. (The latter recorded and mixed this album.) Kouen Kyoudai consists of two long tracks, totaling some 47 minutes. While it appears freely improvised, it's actually quite carefully constructed. "Slide" opens gradually with shimmering organ and synth drones, some controlled feedback, and a lush backdrop of restrained noise. Ishibashi's piano enters at four minutes, playing open, ominous, investigatory chords. Her drum kit, hammering away at an emerging wall of sound, adds an array of jazz syncopation, circular rhythms, and fills and rolls into the sonic maelstrom. By contrast, "Junglegym" begins with the lower register of Ishibashi's piano, illuminated by Akita's sonic drones and sampled percussion wizardry comprised of indefinable sounds. The piece eventually picks up in intensity and busy-ness, while remaining musical and beguiling throughout. Ishibashi's flute makes a welcome appearance, too: the softness of her phrasing adds contrast and implied melody. This duo chases the Muse through a labyrinth of dynamics and cascading sounds before closing in a near whisper. Kouen Kyoudai is a collaborative offering in every sense of the word. The listener encounters Akita at his most musical and studied, though he is no less creative. Simultaneously, she gets to hear Ishibashi's wider, deeper talents on full display -- they have only been hinted at on her Drag City records. For fans of imaginative noise and communicative improvisation, Kouen Kyoudai is a gem. ~ Thom Jurek, Rovi