In the '60s, Steve Reich experimented with various simple processes to generate a series of pieces: for example, he might have two performers playing the same part, but then after a certain number of repetitions one performer delays the part by one beat (putting the two performers one beat out of phase), after a certain further number of repetitions, there's another single-beat delay (two beats out of phase), and so forth...until eventually, the performers are back in unison again.
It occurred to me that it's very simple to create such a process piece using digital editing software: all you have to do is create a cell, replicate it, replicate the grouping, but then shift its beginning a certain length of time.
So, I decided to sample the opening guitar riff from Derek and the Dominos' "Layla" (I intentionally chose something very familiar). I repeated it 128 times - then I duplicated those 128 times, but shifted the whole thing forward by four bars and one eighth note. Every four bars, I added a silence equal to the length of one eighth note. (In other words, I took the length of the cell - a two-bar phrase, so 16 eighth notes - divided it by 16, and incremented everything forward by that length, every four bars.) Then I eliminated the material beyond the ending of the original 128 cells.
This was interesting enough...but once you got what was going on, the rest was predictable. So I decided that I'd then take the second set of cells, duplicate it, then insert it four bars and one eighth-note later - so after eight bars and a couple of beats, there were three Laylas playing. Doing this onscreen, the visual symmetry of what I was creating led me to the next step: I eliminated not only any cells that went beyond the original ending, but symmetrically trimmed off four cells at the end as well, in each track (so that at a certain point, the three Laylas would reduce to two). On the screen, what was beginning to emerge was an inverted pyramid, with each track having eight fewer cells than the one above it. Each track was shifted forward another eighth note. So I continued, until at the peak of the music (right in the middle), there are nine different "Layla" cells playing.
That's almost what you're hearing. Purists probably would have left it alone at this point (true purists would have been irritated that I'd used the re-balanced 20th Anniversary version of the song...then, those purists would have nothing to do with the whole project...). Although it was interesting to hear all nine versions pile up in the middle of the piece, I decided it would be fun to be able to hear a bit more detail - so I left tracks 1, 2, 5, 6, and 9 alone, but shifted tracks 3 and 8 three-quarters to the left channel, and tracks 4 and 7 three-quarters to the right channel.
So there you have it: "Laylaphase."