I have a Roland A-37 and I use it to control not only a Motif ES rack and a Fantom XR but my Tyros 2 as well (talk about a 76 notes Tyros...
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As Fran pointed out, it can transmit on two separate zones (upper and lower) and you can choose just one of them or layer them together.
The cool thing is that you have 128 memories, completely programmable; it takes a little work, but you can definitely do what Donny is asking: select a different sound/registration on the Midjay or evey other module of your choice.
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Korg Kronos 61 and PA3X-Pro76, Roland G-70, BK7-m and Integra 7, Casio PX-5S, Fender Stratocaster with Fralin pickups, Fender Stratocaster with Kinman pickups, vintage Gibson SG standard.