In June 1965, Coltrane and 10 other musicians recorded "Ascension", a 40-minute-long piece without breaks that included adventurous solos by young avante-garde musicians as well as Coltrane, and was controversial primarily for the collective improvisation sections that separated the solos. Dave Liebman later called it "the torch that lit the free jazz thing.". After recording with the quartet over the next few months, Coltrane invited Pharoah Sanders to join the band in September 1965. While Coltrane used over-blowing frequently as an emotional exclamation-point, Sanders would opt to overblow his entire solo, resulting in a constant screaming and screeching in the altissimo range of the instrument.