No game interface exists or has been disclosed yet so we can't say for sure how players will interact with instruments to make music.

I don't think player knowledge is a requirement for any aspect of the game including playing musical instruments, but what player knowledge will affect is how good you'll be at it. So while you may be able to play an instrument without knowing anything at all about music, you probably won't make very good music either.

Well I am expecting it to be some kind of guitar hero style UI. My opinion is because SBS tends to want more action type UI for skills and I know they want controller support.

Scribes will have the ability to compose music and I would think that music performers would play that music through some kind of action UI interface either by keyboard or controller.

Maybe after reading the sheet music that would become a knowledge technique to the music performer.

This is something I am really looking forward to finding out!

I play at least 3 instruments in rl and have done some goofing off with composing. If the scribe instance is accurate with in relation to the musician, that would be awesome! The closest game i can remember that had music composition was All points bulletin. It had a midi based music creator that allowed you to write like basically a fk you theme song to your enemy you killed lol.

I would love to see some sort of action based UI, one that allows you to physically place your fingers on the keyboard, and press keys to relative notes to play those sounds in the game world. Rust does something close, and garys mod has a mod to where you can sit on a piano and do exactly as stated.

For something like that to be developed, you'd need to create the sounds for the instruments, which means playing and recording each note on a separate sound. As you get into the gui development, to blow into a woodwind instrument you could press space key-press, and then one of the relative notes on other key-presses in order to play that sound in the in game world. For guitar, that would be a bit more involved, but you could do a simple scale that would be allowed to be played for starting off. I've also worked with unity engine for game design, so seeing these types of functions, and functionality in my head are easy.

I too am really hoping that a music system is included. I come to this from LOTRO, which uses ABC files for playing solo/band arrangements, and also has a system of assigning hotkeys to play individual notes freestyle. Allowing scribes and musicians to advance such skills sounds natural for this setting.