Reading Philip Glass's memoir Words Without Music, recently, I realized that I didn't have a recording of his seminal Music in Twelve Parts, a work Glass composed between 1971 and 1974. This music was written in a style similar to that of much of Einstein on the Beach, which is the Philip Glass music I like best (along with his solo piano pieces). So I bought the 2006 live recording that Glass made for his own label, Orange Mountain Music. (Amazon.com, Amazon UK) This set is on four discs, and runs for 3:24.
When Glass wrote this work, it was just the first part, and the title referred to the twelve lines of counterpoint in the piece. But someone he played it for asked him where the other eleven parts were, and he decided to writ them. Glass has said, about this work, "It was a breakthrough for me and contains many of the structural and harmonic ideas that would be fleshed out in my later works. It is a modular work, one of the first such compositions, with twelve distinct parts which can be performed separately, in one long sequence, or in any combination or variation."
The piece is scored for three electric organs, two flutes, four saxophones (two soprano, one alto, one tenor) and one female voice. Only the organ is heard throughout; each "part" uses a different combination of instruments, with seven musicians playing, and one engineer doing the live sound mix.
It's a fascinating work, which shows the range of what Glass's minimalism was like in the early 1970s. Each of the parts is different, yet they share the same rhythm. Like all of this music, it's not for everyone; and you might find that some of the parts aren't to your liking. When I listen to Einstein on the Beach, there are parts I don't care for, and skip: the ones with the really loud, harsh organ. There's not much of that here, but there are a couple of parts with a similar sound.
In any case, if you like minimalist music, and aren't familiar with this work, it's one to hear.