 Although today "free jazz" is the generally used term, many other terms were used to describe the loosely defined movement, including "avant-garde", "energy music" and "The New Thing".During its early and mid-60s heyday, much free jazz was released by established labels such as Prestige, Blue Note and Impulse, as well as independents such as ESP Disk and BYG Actuel.Free improvisation or "free music" is improvised music without any rules beyond the logic or inclination of the musician(s) involved.