Kingdom of Knuffel

You have the ability to skillfully play every musical instrument

You can be invisible

You are immortal in that you never age or succumb to illness; other injuries, etc. may still befall you, however.

You can cure people by playing them a melody

You identify any substance, and its properties, with a touch of your finger. Complex formulaes or proprietary blends, no barrier to you.

you can charm anyone with your music

You can see any distance, in any lighting (or lack of lighting) with perfect clarity.

You can also adjust which wavelengths you use to see. UV, radio, heat, whatever.

No one can possibly lie to you

You have a personal pocket dimension and can put whatever you want/need to into, and take it back out again.

You use your harp to summon invisible creatures to do your bidding.