Hi Ken, that X8 allows you to mix up to 8 audio tracks with your midi tracks. I would be looking to using Real Tracks on the audio tracks and just using midi for certain song specific licks that you need. I've mixed a bunch of midi files like that using Real Band. I start with a decent midi file and then replace what I can with several RT's like piano, bass or guitar. There is nothing like hearing a real acoustic bass RT instead of a midi acoustic bass no matter how good the sample is. You could mix in a RT Soloist as well. You set up the file so you and your partner are trading solos with a RT soloist. Also, a lot of songs have cool drum fills or punches to go with the tune but for the most part the drums are just grooving along. I guarantee you the midi drums in the X8 have a sound quality very close to a RD track. Generate a RD track but mute it or delete it for the one bar that has a cool lick or punch and let the X8 midi drums do that then you're back grooving with a Terry Clarke RD. Lots of times I will use several different RD tracks, including percussion and then figure out which one I want to use in which part of the song and take those parts and put them on one track and delete the rest. You can come up with an unbelievablly great sounding drum/percussion track that way. A knowledgable listener will be asking you how the heck did you do that?
I use a Korg Pa1XPro for live playback of midi files on a gig when I need that but it doesn't have the option to mix audio files with the midi, I wish it did. Good quality midi bass and drums do sound pretty good and I'm sure your X8 sounds good too but the RT/RD's take it to a whole other level. You can't beat live studio players.

RB is definitely the program you want to use for this not Biab.

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