For half a century, Terry Riley has found himself filed alongside fellow American composers such as Steve Reich, Philip Glass and John Adams, whose minty-fresh minimalism sounds as if it has been plotted on graph paper. Riley’s music is, in the best possible way, often much messier than that of his peers, and it seems to have become even more gleefully chaotic in recent years. The minimalist rigour is there, but it has been warped and reshaped by Riley’s multiple interests, not least his love of Indian ragas, Balinese gamelan, west African percussion and jazz. It reminds us why the Who’s Pete Townshend, a fan of Riley’s work, once said “the only thing minimal about Riley’s music is the limitation of the audience”.
Tonight’s show is as close to a jazz performance as you are likely to see by Riley, or indeed any other contemporary music composer. Riley shares the stage with his guitarist son Gyan Riley, collaborating in a series of loose improvisations. It is as joyously ramshackle as this venue, which resembles a large scout hut that has been painted white to convert it into an art gallery.
Riley switches between several instruments. He plays clavinet and zither vamps on an electronic keyboard, a lengthy snake-charmer solo on a large melodica and sings deep ragas in the Kirana style, as taught to him by the Indian musician Pandit Pran Nath. During one memorable piece, just after the interval, he plays a woozy synthesised string section, pitch-shifting it so heavily it sounds as if an orchestra is melting.
But his main instrument tonight is the Steinway grand. Riley is not a jazz pianist by any stretch of the imagination, but he has explored the genre more thoroughly than many other minimalists: he studied ragtime with the San Francisco pianist Wally Rose, used to play in piano bars in 1960s Paris and is adept at rattling through cycles of jazzy extended chords. There is something appealing in his mix of ostinato left-hand vamps and metrical right-hand improvisations, which sound like Bach trying to do bebop.
However, it is Gyan who injects a real jazz sensibility into proceedings. While Riley Sr’s improvisations are consciously stiff and repetitive, Riley Jr’s are loose and spontaneous. Gyan switches to a nylon-string acoustic for one solo piece, Lookout Hill, from his latest album, Sprig. It sounds exactly like a Philip Glass-style minimalist piece arranged for guitar: a complex arpeggio is repeated over and over, changing incrementally and becoming more complex through accretion. It is a staggering solo, and the only written-through moment in the programme.
Otherwise, Gyan stays on electric guitar, playing scribbly counterpoint to Riley’s piano explorations. Frequently, his improvisations include adding random splashes of colour, bending notes and substitute chords. He also uses a variety of effects pedals – auto-wah, digital delay and even heavy metal levels of distortion. By the closing piece, as Riley triggers hypnotic samples, Gyan is freaking out on a distorted guitar, transforming the meditative mood into one more akin to a rave. Aged 83, with a long white beard that seems to confer upon him a priestly appearance, Riley grins through the chaos.