How do you use the Harp in The Hole?

[SquirrelTeeth]

I have unlocked the room where the harp is and I can stand in front of it, but there is no note generation happening... I have no notes.

How do you actually turn this thing on? There is a space on the top left that says, 'locked"
How do I open it?

[Bulvej]

Drag your mouse/finger across the strings.

[archmag]

You charge at least 100% note power (or whatever it is called, the resource which keeps increasing with time in the top left corner), change notes which you want to use (initially just C is enough as it generates notes resourse but later you can switch to other notes, D for opals, for example) and then hold left mouse button and drag cursor across the strings to play them. You can play them even without 100% but they won't give anything.

You can see what each note gives in tuning the harp mode. They have two bonuses, one which depends on total % of power you accumulated when you play the harp and another which depends on their level (you gain exp for each note when you play a string with that note active).

[SquirrelTeeth]

I was clicking, but not dragging. I get it now, thank you!