Hi and welcome!

Midi files come in two flavours - type 0 and type 1

Type 0 have all the instruments on one track, type 1 has each instrument on a separate track. Sounds like you've got some of both

I'm not sure how to get round this in BIAB, but if you Google 'midi file converter' or similar, you should be able to find a small app that can convert between the two


regards,


Martin