I bought a looper pedal: the TC Electronic Ditto Stereo. The first thing I tried was this ambient improvisation, where I use the looper to layer notes of the Volca Bass.

If you're unfamiliar with loopers: when the Ditto's LED is red it's recording, when it's green it's just playing. The first recording determines the length of the loop. After that, you can just keep recording and add layer after layer.

Korg Volca Bass
TC Electronic Ditto Stereo
GFI System Specular Reverb V2
Arturia Keystep
Miditech MIDI Thru/Filter
Behringer XENYX QX1002USB

Recorded with iPhone 7 and Behringer UCA202.