An estimated 20,000 to 30,000 listeners of all ages, genders, races, religions — Americans and visitors from abroad, too — enjoyed the directly expressive, highly personalized music of Pulitzer Prize-winner Ornette Coleman as the finale of the outdoor Chicago Jazz Festival last Sunday night. The attentive, mellow and celebratory audience response, including a standing ovation throughout the 5000 seats nearest the bandshell in Grant Park, suggested that improvisation created without a priori conventions or artificial constraints, which Coleman throughout his remarkable career has alluded to as “free jazz,” “harmolodics” and “sound grammar,” upon easy access and unpressured exposure, is as natural as breathing, feeling and talking. As Coleman declared on one of his recordings almost 50 years ago, This is our music.