Enjoy Frank Zappa’s tricky compositions, but wince at his sneering lyrics? This almost entirely instrumental 1969 album was the first of several bones he threw to fans of fusion and prog. The buzzing horn charts and mock-medieval fanfares of “Peaches En Regalia” are surprisingly close to early King Crimson, but the stomping, metallic “Willie The Pimp,” with vocals by Captain Beefheart and searing electric violin from Don “Sugarcane” Harris, and the hard R&B boogie of “The Gumbo Variations,” featuring fierce saxophone soloing from Ian Underwood (and more Harris), are the real meat of the record.

In summer 1969, shortly after the final Mothers gigs, Zappa holed up in the studio with Ian Underwood and a cast of top-flight studio musicians (Max Bennett, Shuggie Otis, and John Guerin, among others) to make his first proper solo record. In a mix of tightly orchestrated compositions and loose jams, Zappa leaned into jazz-rock, making a “movie for your ears.” From the dense layers of overdubs on “Peaches En Regalia” to the lengthy solos on “The Gumbo Variations,” this is Zappa in full flight, showing both guitar heroics and a knack for melody. It’s an album both structured and spontaneous.