This exercise is in some ways related to the last one. However, it is going to allow us much more direct control and rely less on chance.
Composition by subtraction is an idea explored by Brian Eno on Before and After Science, an album that marries pop with avant garde experimentalism, and one I highly recommend. The idea is simple: sculpt your song out of a mass of tracks, eliminating one track at a time.
So here’s how I’m suggesting you proceed:
STEP ONE: LAYERING
Start by recording a basic idea for a song. It doesn’t matter where you begin. It can be a simple beat, a chord progression on the guitar, a sung melody, a series of licks, or weird percussion. That’s up to you, and I recommend trying this exercise with different kinds of starting points.
Now start layering parts on top of your foundation track. Unlike the Invisible Layering exercise, you should keep all of your tracks unmuted.
So far, this just sounds like the normal process of writing a song track by track. But now things get more out of control. Keep layering tracks; don’t stop when the arrangement sounds filled out. If possible, try to use as many different instruments, sounds, textures, etc. as you can.
Now keep layering (even as the arrangement becomes more and more cluttered). Don’t worry about how noisy it’s getting; just keep writing and recording new parts. Try to make each new one unique.
There will come a point where you’re not sure how to fit things in anymore. Don’t let that discourage you; just keep going. If your new ideas start to sound random, keep them anyway.
It’s up to you how many layers you add. I recommend putting down quite a few. The more layers, the more you’ll have to work with in the end.
STEP TWO: SUBTRACTING
When you feel you’ve completed your massive noisy masterpiece, it’s time to move to the next stage. This is where the composition by subtraction comes in.
The process is simple: just start muting tracks one by one, seeing what different combinations sound like. The real work is in demoing different arrangements.
Think of your wall of tracks as the stone from which you are carving your song. Hidden in there are a number of really interesting combinations you would never have written off the top of your head. Your goal is to get in there and find them.
I can’t promise you’ll come up with the next Top 40 hit this way, but you might just discover something you love.