Servo to pluck sound staves

if each of the 13 rods is hit by the solenoids with 10 ms in between, the first solenoid would get 130 ms to get ready.

I think that is pushing it for a solenoid. If you fire one before it has retracted fully you don't get the same "slap" because the core hasn't time to accelerate in the magnetic field.

Try the slapping idea with one motor per rod.