Terry Riley's performance notes for In C give a lot of leeway to the performers, within the general confines of its 53-pattern structure and an insistence on synchronized time and tempo. For example, he writes, "Any number of any kind of instruments can play. A group of about 35 is desired if possible, but smaller or larger groups will work. If vocalist(s) join in, they can use any vowel and consonant sounds they like."
It is an invitation to experiment, and a lot of different types of ensembles have taken Riley up on it over the past 46 years. Among the noteworthy:
Nov. 4, 1964: The first performance of In C, at the San Francisco Tape Music Center, by a small group that included Riley's friends Steve Reich and Pauline Oliveros. In David Bernstein's oral history, The San Francisco Tape Music Center (2008), Riley says there is a recording of the concert, but adds that "it's only good for historical curiosity," because the microphone was positioned in front of a tenor saxophone that drowned out all the other instruments.
1968: The first commercial recording, featuring Riley on saxophone with musicians from the New Music Center in Buffalo, N.Y.
1970: Clocking in at 30 minutes, Walter Boudreau's jazz-rock group L'Infonie's version, recorded in Montreal, may be the gateway version for rock fans. Bombastic but celebratory, this raucous recording channels rhythms and energy from rock 'n' roll, and even a touch of that genre's insouciance; a misreading of the score led to this vamped-up execution of the piece, and the tape ran out before the performance was finished. Electric guitars aren't prominent here, but you can bet some brass-fixated, percussion-heavy, repetition-loving indie rock bands cribbed from this recording. It's a joyous noise, and with this performance you can hear why some of the moldier figs turned their noses up at Riley and why younger generations continue to embrace him.
1990: Piano Circus, an ensemble of six pianos, released a short, fast, all-piano rendition.
1998: There can never be a definitive recorded version of In C in the way there might theoretically be with most traditional classical pieces. Nevertheless, Bang on a Can's version is a great textbook, a user-friendly beginner's guide to what the piece can be. Recorded in 1998 and released in 2001, it's instantly recognizable and relatable to older recordings of the piece, but the unusual instrumentation of the 10-piece ensemble—violin, chimes, clarinet, electric guitar, mandolin, pipa, marimba, and vibraphone, among others—creates an eerie new sound. It should be a wonder to hear what this group does with it at the Tennessee Theatre this weekend.
2002: Acid Mother Temple and the Melting Paraiso U.F.O.'s recording begins traditionally enough, with the recognizable motif toyed with on glockenspiel while a synth drone builds in the background. But it doesn't take long for AMT's cosmic space rock to kick into overdrive, rendering the composition almost unrecognizable. Apparently Riley wasn't too thrilled with a live version the Japanese psych band played at his 70th birthday celebration, suggesting they may have taken it further out than he ever intended. The album also features their own variations on Riley's compositional methods, "In E" and "In D," neither of which sound much different than their take on the original, or many of their other drone- and groove-heavy freak-out recordings, for that matter. None of which makes this music any less awesome or impressive, of course.
2002: The Styrenes, an avant-punk band formed in Cleveland in the 1970s, eventually moved to New York City and, after various lineup changes and a half-dozen albums of original material, recorded a rock-based variation on In C that suggests the music could work as well in a grimy club as a concert hall.
2009: In a version on an album called Minimal Flute, Swiss musician Hans Ballmer dubbed himself over and over to create a one-man flute orchestra.