This classic July 1964 trio set, Albert Ayler’s first for the storied avant-garde label ESP Disk, is an excellent introduction to the doggedly nonconventional tenor saxophone sound that changed improvised music forever. With bassist Gary Peacock and drummer Sunny Murray, Ayler largely broke free of tonality and regular pulse, instead mining a vocabulary of timbre and attack, yielding a raw spiritual cry that spanned the range of the horn and often reached beyond it. It was arguably the most influential tenor sound after Coltrane’s, a guiding light for such heirs as Peter Brötzmann and David S. Ware. Murray’s flexible, reactive feel pointed the way forward for many drummers after him as well. But in Ayler’s music, the initial themes (on “Ghosts,” for example) could be disarmingly plain and simple, like fanfares, harking back to the catchy melodic material of earlier jazz eras. Ayler also employed far more vibrato than was common in the days of John Coltrane’s ascendance. The wavering tone at the end of “Spirits” almost recalls the stylized 1920s saxophone sound of Frankie Trumbauer. His dynamic shifts (loud to soft) and sly textural subtleties could surprise, but mainly the intensity throughout Spiritual Unity is full-blast, a rhetoric of unfiltered emotion, pure and true (“The Wizard,” “Vibrations”). It was punk rock before punk rock.