You need to think musically, not based on DAW math.
12/8 time signatures have tempos around 40-90, and are counted as 4/4, not in “12”
The tempo of the 12/8 song you posted is 80, not 120 as you’ve set it up in reaper.
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If you were thinking musically, that slow blues shuffle you posted would have just been done in 4/4 at tempo of 80, and would never have needed an artificial transformation to a tempo of 120. You would have just stayed in 4/4, and maybe added a few tracks of your own playing, and ended up with a great sounding blues song.

Just tap your foot … that’s the tempo. These compound time signatures like 12/8, 6/8, 9/8 are for the NOTATION display only, and they’re not how you play them musically.


Have Fun!
Peter Gannon
PG Music Inc.