Rikki, you are right Bandstand does not accept bank changes. It adhers to the GM Standard....but it nonetheless has 9 different drum kits which I would like to access via the styles (or midi files). So if I use the Custom or XG setting in OMB the styles call up the appropriate drum kits. This leads to going thru the styles and ensuring that the correct instruments are called up for all the other parts of the style, e.g., bass calls up bass and not a piano.
Furthermore styles or midi files which change instruments on the fly would see a short break in Bandstand while it calls up the instrument requested....not so good. The answer would likely be, as Esh pointed out previously, to use a Flash Drive (much faster than a hard drive). In future computers will likely have enough RAM to handle this sort of thing with ease.
I plan on pressing ahead with Bandstand and determined to make things work.