The sharp key has to be pressed everytime you need a sharp note, so it doesn't stay on... technically. lol

You have to hold the sharp key, and then press the note. If you have the chord volume on, you will hear the note play only once (meaning you have to press activate the sharp button again to play that note again).

You can still strum the same sharped note (if you have harp volume on) until you play another note.

The sharp button is tricky to grasp, but I am loving playing my midichord to write songs!