> No, I can't be bothered to learn piano scales. I expended my mental capacity for it on guitar already.

It’s a lot easier on the piano. The keys are laid out as sheet music, very convenient if you know a bit of music theory.

I have a couple of groovebox-style machines (Korg Electrobe 2, Novation circuit) and they will let you select a scale and then the pads are locked to that scale. And then the internal synth and the MIDI out will just be in that scale/key.

I don't find it super useful-- I'm not bad at pianos/keys, but it does simplify note input quite a bit if that's what you're looking for.

Well if you just keep to the key of C you can just play white keys. Some controllers have transposition settings on them! If not you can use a midi effect in your daw to transpose to another key, too. But really if you can already do things on guitar then piano will beat lot easier and probably even help your guitar technique as well.

Try a Launchpad X. It lights up all the pads that are part of a scale.