Perhaps....


Maybe you can do this using a DAW. It would take planning and forethought....

Render the parts in BB and export tracks. You would need to make 2 versions of the song. One in one tempo and the other in a doubled multiple or halving of the original tempo. Add the needed measures.... the faster one would need to have exactly twice the number of measures as the slower one....

Choose the tracks you need to make the end product. You could even splice a part.... drums for example.... from both tracks so the fills are correct.

I have contemplated something like this but have never felt the need to actually spend the time to try it. I normally take a different path like changing the song or putting it into the ash heap.

You can find my music at:
www.herbhartley.com
Add nothing that adds nothing to the music.
You can make excuses or you can make progress but not both.

The magic you are looking for is in the work you are avoiding.