Well here’s my first stab at a shoulder synth form. It’s purpose is mostly to place the idea in my mind around my neck and get feel for what dimensions work, what edges should be smoothed, and what just plain bites.

It holds an Arturia Minilab which makes it a pretty useful mockup, but this is just the start. Any decent keytar needs modulation controls on its neck, a decent keybed, and at least 3 octaves.