Les McCann’s return to the Montreux Jazz Festival in 1972 brought to a close a cycle that began in 1968 with Swiss Movement, McCann’s hit live album with Eddie Harris. With the release of Layers in 1973 he graduated to another plane of electronic discovery. The album documents McCann’s love affair with the ARP synthesizer, a machine with an infinite number of sonic possibilities. In the liner notes to Layers, McCann wrote that his goal was to be the orchestra he heard in his head. Throughout the album one can hear the keyboardist stretching to imitate the sounds of woodwinds, brass, strings and even electric guitar — the groaning feedback-like blasts of “Let’s Gather” are reminiscent of Jimi Hendrix’s work with Band of Gypsies. While his band keeps the songs grounded in gritty funk, McCann conjures an astounding array of shapes and colors and textures. Layers might be the most generous of all McCann’s albums, if only because it gives as much entertainment to the listener as could be contained on a slab of vinyl. The album is at once the ultimate psychedelic light show and the pinnacle of stoned-soul cool, and the songs refuse dullness even after repeated listenings.