The Association for the Advancement of Creative Musicians (AACM) was formed in mid-1960s Chicago as a way for predominantly Black composers to create a whole new performance environment and support system for their work. Henry Threadgill is among those who came up through the AACM and went on to major recognition—including a Pulitzer Prize for his work on Zooid’s 2015 release In for a Penny, In for a Pound. It all started with the trio Air, Threadgill’s first proper group—or, more accurately, his first proper collective, featuring Fred Hopkins on bass and Steve McCall on drums and percussion. Released in 1975, Air Song was Air’s debut album, the first of two efforts for the Japanese Why Not label, before the trio moved on to Black Saint, Nessa, and the higher-profile Arista/Novus. While Threadgill’s main sax soon became the alto, on virtually all of Air’s recordings, he played tenor, baritone, and alto equally—as well as flute, executing high-level ideas with a personal style all the while. In fact, the four tracks on Air Song—all of them Threadgill originals—are each wholly devoted to one of the four woodwinds: “Untitled Tango” is a choice bit of tenor tumult; “Great Body of the Riddle” is eloquently stormy bari sax; “Dance of the Beast” reveals that bright and inventive alto sound familiar from Threadgill’s post-2000 work with Zooid; and “Air Song,” as its title suggests, employs the gentler, more spacious textures of flute, bass, and drums to bring the album to a close. On one level, Threadgill’s Air was a continuation or expansion of the “chordless” trio concept elevated by Sonny Rollins on recordings like Freedom Suite, or by Ornette Coleman on his Golden Circle Blue Note recordings of 1966. Without piano or guitar feeding chords to the horn soloist, the music opened up, offering a wider space for Threadgill, Hopkins, and McCall to reveal their outsize personalities.