Hi Barry,
Please correct me if I'm wrong.
How I'm interpreting your post is that you'd like to obtain some instrumental sound from the internet and then, loading that sound into BIAB, you want to use a keyboard to change the sound's pitch, as determined by the keyboard, so that the sound can play a melody, etc.
BIAB does not do this natively. To accomplish this you could convert the sound into soundfont format using appropriate software or use BIAB/RB to save the sample with acidized information and then load it into a suitable program like SFZ (found
HERE). In theory, the VST could then be loaded into BIAB and the instrumental sample played.
I'm just giving this a test run at the moment. I'll be back with additional information and whether or not it worked ok.
Regards,
Noel