I was looking for a solution for learning one handed keyboard playing. It dawned on me that is exactly what an accordion player does. Then while looking for lessons on-line I came across the Horner midi controller app on my Ipad Pro. I used core midi to Sampletank, Velcro to the iPad cover and hoocked up the old Qu to my camera connection and now I can play chords with my left hand and the melody on the Qu with my right. id (easily said than done) Going to be a learning curve but you have a lot more possibilities for sounds and it is portable. You can charge the iPad with the camera connection via wall wart or a rechargeable usb battery. I think this @2lbs and easily disassembled. You can plug in headphones so no one has to hear you practice. Plug it into to your amp and everybody around will remember you. If you want to stand up and play you could velcro it to your shirt but it is best played sitting down like an accordionest. Look ma no bellows! If you have an iPad pro with this type of case and the Qu you are talking velcro plus the Horner apps and what ever midi app or program you interface with. I had all of that so it was less then $20 for me. I don't like the lightning connecter sticking out but felt is was better down then up against my chest. I might velcro something stiff to prevent it from being bent. I may cut out some kind of insulated rubber sheet with holes that will stay on the left side screen to help find the left hand buttons and prevent from accidentally hitting some of the other set up options. I am sure with a lot of practice that will be less of a problem. Work in progress but it has great potential.
Next I am going to use the Apollo app to send wireless midi via Bluetooth Le to my Macbook and link it to a guitar strumming app so the chords will be strummed using channel 1 and the melody on chan 2 to some other sound. I haven't found a strumming midi app for iOS yet except for Capo. With that app you are limited to the number of chords and it is not easy to set up for control. I want to sound like anything other than an accordion
If there are any accordionist reading this, note that I can where my watch on my left wrist and you can't because of the left hand strap on the accordion. Yet another advantage.
You can also just forget the Horner app and put this rig on your lap and it is a nice holder to play two handed and still be able to change things on, say, Sampletank, on the top portion of the screen and if you need to get to the bottom, just lift the cover up. You could also use a sheet music app like ForeScore with a bluetooth peddle for page manipulation or just use your finger to move the music.
I also was thinking of using my 12 Step to play chords but could not find a way to interface the Qu and the 12 Step into one midi signal. I am sure if I spent another $500 I could have ragged something up but it would have been too complicated. The ol' "Keep it simple, stupid" solution.