What better soundtrack could you have for celebrating Independence Day than the most unbound kind of music around? Hell, it’s right there in the name: free jazz. These are the sounds of liberation, of minds and spirits set loose from all constraints. We start at the birth of free jazz in the early ’60s, when visionaries like Ornette Coleman were looking beyond the horizon line to determine where jazz could go next. For Coleman and legions of others to follow, the answer was unfettered improvisation, whereby the melodic, harmonic, and rhythmic settings could shift on a dime, determined by the flow of the musicians in the moment. Ornette dubbed his 1961 album Free Jazz, giving the genre a natural tag. No longer tied to any kind of conventions, free-jazz players invented musical languages of their own, and although the first bursts of the music may have all been energized by a similar spirit, every musician’s artistic argot was completely their own. The light, darting lines of Don Cherry’s trumpet, the industrial-strength blast of Albert Ayler’s saxophone, and the heady abstractions of Andrew Hill’s piano, for instance, were islands unto themselves, but anybody was welcome to visit.Free jazz was also the sound of liberation in the sense of African Americans boldly defining their cultural identity, as groups like the Art Ensemble of Chicago did with their Afrocentric, unfailingly idiosyncratic musical statements. But as subsequent generations and cultures took up the free-jazz mantle, the music moved in multitudinous directions, from the postmodern pianistics of Matthew Shipp to the visceral trumpeting of Steph Richards and beyond. There are a couple of Europeans in the mix too, but jazz is one of the ultimate American art forms, and the most untrammeled end of its spectrum makes the ideal musical companion for marking America’s anniversary of independence.