More octaves in performance mode

I recently unlocked bard but then I noticed that I only have 3 octaves...
You can play a lot with 3 octaves but 4 octaves or even more would be a lot better. With 4 octaves you could play some songs in octaves with 5 octaves both hand in octaves. There are enough keys on a keyboard to give 4 ore more octaves an own key.
When you have a keyboard or piano you can plug it in your pc, so you have more keys to play. This would give a lot more choices.

Sry for my bad englisch, this is not my native language

Support this. Player concerts (even solo) are a really cool part of the game. I support anything that makes it more fun for the performers.