Birthday boy Sam Rivers would have turned 95 years young today. Many know him for his brief stint in the sax chair in @milesdavis embryonic Second Great Quintet where he replaced George Coleman. Rivers would last only briefly (appearing on ‘Miles in Tokyo’) before being replaced by Wayne Shorter. Rivers then stepped out as leader and sideman for Blue Note, Impulse!, Black Saint, RCA, Horo and his own Rivbea label. Rivbea was a portmanteau of his name and his wife Bea, and also the name of their loft where numerous free jazz sessions were held in NYC during the 70s. This two-fer contains a pair of Blue Note sessions from the 60s: one is a quartet under pianist Andrew Hill’s leadership (later released on CD as ‘Change’) featuring Walter Booker (bass) and J.C. Moses (drums) recorded 7 March 1966; the other a sextet under Rivers’ leadership (later issued as ‘Dimensions and Extensions’) recorded 17 Mar 1967 featuring Donald Byrd (trumpet), Julian Priester (trombone), James Spaulding (alto sax/flute), Cecil McBee (bass) and Steve Ellington (drums). Both share a lot of musical DNA—an elusive tonal center, playing that stretches harmonic boundaries and timekeeping that’s not exactly built for clapping along. The compositions are complex and challenging—there’s a lot of “out” playing here as the knotty heads of each tune serve as a launchpad to some seriously ambitious and adventurous group improvisation. Dig deep—there’s swing and beauty though both can be elusive, and don’t believe anyone who says “it’s out there, but still really accessible!”. It’s not…certainly not in the way that Rivers’ earlier Blue Note records like ‘Fuchsia Swing Song’ or ‘Contours’ can sound like hard/post bop records with occasional sharp elbows. ‘Involution’ isn’t for beginners. Or those who are learning to waltz. This is challenging but ultimately really rewarding music. As I’ve previously noted, this beige-cover Blue Note Classics series is uniformly excellent—great pressings, informative liner notes and material that’s otherwise difficult to find. They are also often reasonably priced and pretty easy to find in the wild. Recommended