Hey, I know how to get the midi file
1. use a unity asset extractor (assetripper are examples) to extract bb+ files in Baldi's Basics Plus\BALDI_Data
2. drag everything from baldi_data into your chosen asset extractor and then export them to a folder on your computer
3. you can find the midi files in folder name -> the folder in that folder (sharedassets2 for example) -> exported project -> textassets (the format used in bbcr is .bytes. you can simply rename the file type part into .mid so that it can be used as a midi file. Powertoys recommended)