The summon instrument spell says that the conjured instrument plays only for you.
How does that work exactly?
If I hand it to someone and they attempt to play it, doe it disappear? Explode? Break? Remain silent despite the physical act of playing it? Perform so poorly that the resulting cacophony could not be considered music? What exactly happens?
What if they tried to use the instrument in a non-traditional manor, such as by turning a violin into a percussion instrument by rhythmically tapping on it or banging it against things? Does it make any noise then?