To create this sound I started by programming a beat. In this case I pitched each slice of the beat individually to create a variety of pitches in the loop. Once I was satisfied with it I rendered it to a clip and applied a plugin by Paul Kellett (MDA) called Tracker, distributed by smartelectronix. Tracker tracks the frequency of a sample with a waveform, such as a sine wave, and then allows you to transpose, slide between pitches, adjust the mix and so on.
Running drums through Tracker can create some interesting and unpredictable melodies. At the start of this clip I left the mix at 100%, only hearing the melody created by the pitches tracked, then adjusted it down to zero by the end so you can hear what the beat sounds like without the pitch tracking. In front of Tracker I added Beat Repeat and turned it on a couple of times to generate some fills. I touched it up with some tempo delay mixed in here and there for some dub flavor.