If you want backing tracks just search google, it will be easier than making them up.
If you want to make them up the easiest way is open the midi file in RealBand and use virtual instrument on the midi track or generate up comparable realtrack/drums/usertracks.

Biab won't split the mp3 into multitracks

http://www.guitarvoice.com/backingtracks/artist/bb_king
http://www.guitarbackingtrack.com/bts/BB_King.htm

http://www.karaoke-version.com/custombackingtrack/search.html?query=BB+King
http://songgalaxy.com/multi.php
https://www.jamkazam.com/client#/jamtrack/search



https://www.youtube.com/watch?v=1Pp-GmZezx8