On Four Units, four absolute monoliths and foundational masterminds of Japanese modern jazz history—tenor saxophone titan Akira Miyazawa, visionary avant-garde pianist Masahiko Sato, legendary percussion pioneer Masahiko Togashi, and master bassist Yasuo Arakawa—converge to deliver a staggering, historically explosive, and masterfully synchronized studio document. Originally recorded in April 1969 for Union Records and beautifully preserved on this pristine digital edition by the archival specialists at Think! Records, this monumental milestone stands as one of the most towering holy grails of late-60s Tokyo underground exploration. Spanning nearly 40 minutes of immaculate high-fidelity spatial design, the 5-track landscape operates with an intense, lightning-fast, and beautifully complex kinetic energy. The quartet serves as a radical bridge between advanced structural post-bop and completely uninhibited free improvisation, firing off magnificent collective layouts like Togashi's incendiary, polyrhythmic 11-minute title anthem Four Units, Sato's brooding, angular masterpiece Dull Slumber, and a hauntingly deconstructed, modal transformation of the traditional classic Scarborough Fair. Driven by Miyazawa's fierce, biting reed expressions, Sato's clustering piano eruptions, Arakawa's rock-solid acoustic alignment, and Togashi's hyper-fluid, geometric drum propulsion, this pristine archive remains an indispensable cornerstone for serious avant-garde purists and global J-Jazz collectors worldwide.