Some of the more interesting ways imho:
- morphing two different audio or synth tracks into each other with modulation with something like Zynaptiq Morph oder Melda MMorph
- using spectral (Melda Transformer, Zynaptiq Wormhole…), pitch and granular (PitchMonster, Uhbik-G/S…) audio effects to change the sound of an audio or synth track
- using RX or Photosounder to go crazy with an audio track - repaint your audiofile in Photosounder or use modulated effects on frequency bands that you draw in RX…
- import a short audio recording into a wavetable synth such as Icarus or Serum and do whatever you like with it…