First open a new project in Reaper. Press Alt/Enter to open the Project Settings. Set it to the tempo of your first bar in BIAB. Also set the time signature. 4/4, 3/4, etc,... Save and name your blank Reaper project. Now drag and drop your BIAB files to Reaper. What I do is; In BIAB I don't drag/drop my files to the little 4 square thingy. I use the .WAV box with the little microphone in it in the tool bar and choose "Save All Tracks As .WAV Files with options" and I check "Include ACID info".
Another option is to use "Select Midi Super Track for this track" on the Melody track in BIAB. Use the drop down arrow all the way to the right on the Melody Track. It doesn't matter what instrument or style. Regenerate, Save/export as midi. Drag and drop that midi file to an empty track in Reaper. That should set the bar changes, tempo changes, etc,... inside Reaper. Do not put a VSTi on that midi track. It just sort of take command of the tempo, tempo changes, bar changes, etc,... Kind of like a silent metronome for your Reaper project to follow.

Last edited by Tobias; 05/01/20 06:41 PM.
Does the noise in your head bother me ?