Looping is a great way to flex all of your musical muscles. First, you have to write a cool riff; then you have to be able to play it in time, with the proper inflections and attitude. While that’s playing, you have to invent more parts that complement the original and then perform them. With all of that happening, you get to improvise melodies over top of it, which really fires your creativity. You get to be songwriter, arranger, producer, and soloist for your own creation, all in real-time — how much fun is that?
A phenomenon you may notice after multiple loop overdubs, is that some of the parts may become indistinct or blend together in a way that makes the whole mix one-sided-sounding. This is when you put on your producer/arranger hat. You have to make “sonic space” for each of the parts, even if they’re not playing on top of each other and occupying their own rhythmic space. For electronic musicians, changing sounds on the fly is intuitive and a button push away; for guitarists and bassists it’s not so automatic. The point is, giving each loop layer it’s own distinct sound will make them all sound clearer when they’re mixed.
Radical sound changes aren’t necessary to achieve sonic distinction, which is good news for guitarists and bassists. Pickup changes, volume and tone pot moves, or even changing your picking-hand attack will do wonders for changing the sonic profile of a loop layer. If the looper is at the end of your signal chain, you could even step on a pedal for a really different layer.
Think of your loops like a recorded song and how different instruments have their own personality in the whole mix. Playing loops in different registers on your instrument will mimic that. For example: a bass-type part in a low register, a muted part in a high register, and moving chords in a middle register. Add appropriate tone changes to that concept and you’ll hear the difference. Happy looping!