Philip Glass – Music in Similar Motion

From a December 1983 in Electronics & Music Maker interview with Philip Glass:

Glass' first recorded work, Music In Similar Motion, was released in 1969 on his own Chatham Square label, and bears a strong resemblance to Terry Riley's A Rainbow In Curved Air, while the music's sheer minimalism has hints of John Cage or Stockhausen. Until recently, Glass' ensemble began every concert with an excerpt from Music In Similar Motion, and it's a work that's still dear to him as a composer.

'It's got a few nice little compositional tricks in it. For instance there's a bit near the end where it adds and subtracts in the same figure, and that makes the piece interesting arithmetically. Of course, that isn't all there is to it because it's also got a tremendous emotional impact, because it's so repetitive, so monotonous. The reason we always played it first was that people either loved it or hated it. Quite a few people used to walk out after the first twenty minutes. It was a way of finding out which members of the audience were really interested in my music.

'The instrumentation we had in '69 was very basic. Most of the LP was recorded on an old Farfisa organ, a dual-manual one. I got quite attached to it, but eventually I think it just fell apart. Fortunately I succeeded in finding a similar sort of sound on the Prophet 5 a couple of years back, so I've stored that in memory which means I've got access to that organ sound at any time.'