One thing you could try is to open the song with Realband.
Then use the 'make all BB tracks regular tracks' feature.
If you do this RB will only regenerate something if you explicitly tell it to.
And even then you can generate just whatever track/section you want and keep the good stuff.
Yet the tracks are not 'Frozen' as you can still use the pitch shift/key change (etc) on those tracks.

After making them regular tracks you can do Pitch/Key/Tempo shift to your hearts content and just see what happens.
As others have noted, you may get artifacts depending on the material and amount of key change or pitch shift.

But if it goes bad, as long as you don't intentionally save the song in RB as an SGU file and write over the original, you can always go back to the original, since RB saves in the SEQ file format as default.

A couple things about RB that make it better for this type of experimenting:

RB will natively save it as a SEQ file so it *shouldn't overwrite the original SGU, meaning you always have a safe staring point to go back to.

RB allows multiple 'undo' actions, so you can try things and undo easily.

RB makes a backup of the current version whenever you save a seq file. So if you get progress on something you like, then mess it up and inadvertently save it, you can open the backup file from before you saved the goof.

I have often wondered why BiaB doesn't use the same backup philosophy on Save as RB does, since the BiaB files are so much smaller..


I do not work here, but the benefits are still awesome
Make your sound your own!