Take away his credit card
or
It's someone who knows how to play the bagpipes, but doesn't.
or
The fish.
or
Two, one to call Daddy, and one to get the (pick one:) mineral water/Tab.
or
None. music teachers can't afford lightbulbs.
or
A snail because it carries it's home.
or
First they have to agree on which is better; the analog bulb or a digital bulb.
or
Because you better duck when he's pissed.
or
Only one. But he'll leave a big puddle of spit on the floor underneath him.
or