Computer as sound module, exploit MIDI control and your 4 audio inputs.

Drum racks! Or whatever other cool features your program of choice has.

As I play around I resample and save transitions that work. That way I can play around, but still have an overall flow and direction.

Not gonna lie though, I’ve always made music like this and never got on with the idea of using a linear arranger to finish a song, only as a place to get started.