[ad8e]

These are great ideas, and I will implement them.

In the original design, temporary harmony changes (hold-and-release) was the feature of the thumb keys, but there are no thumb keys here, huh.

It's necessary to have stateful harmonic changes, to be able to transition more than a little at a time. But I will add your option too, since it's also useful. I'll need to think about the interface a little bit, since I would either have to add ` or Shift to the keyboard, which will widen it a bit.

When you press these new temporary keys (after they're done), I'll make them change the green numbers. That is hard to do with the permanent purple keys, since they need to keep a base state.