Mutate isn’t as useful as it might first sound. Variation is cool and all, but with no real control over the exact pitch, you’ll get charming results as best. Not out of key or non-scale stuff, it all stays within proper harmonics so it’s predictable enough, but the Deluge does this way better, where you can set up a batch of notes which you decide yourself, and then it can randomly pick from that batch. Gives you control over the composition.