All The arranger needs to be able to do for this purpose is to show on which channels the various style parts are sent out and to mute them internally. The Roland BK-7m can do this. In the Motif, you just have to prepare a Performance ( or it's rather called 'song' there with some of its 16 parts being matched to The respective midi channels. That should be all..

Thank you, Abacus, and Rosetree! This opens up a lot of possibilities.

Midi is something that I will need to look into, as I'm quite inexperienced in this area.

Looking forward to getting an arranger one day, and perhaps an Integra-7, too. It all depends on my financial situation.

If only Roland would turn the Integra-7 into an arranger keyboard! This would take care of great acoustic, orchestral and choir sounds, plus an arranger, with keys!

Thanks again to all who responded!