Sonar x3 might well do this. I have not had much of a chance or time to dig into the new features. I upgraded from 8.5 and even then never learned some of the deeper parts.
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I was thinking also about RB and how that also might work out.
I can see the cut and paste to make different interpretations in a 4 bar loop, I was hoping there's a feature to randomize the loop measures as it's being generated.
Wyndham