When you toss a banjo in the garbage and it hits an accordion.
or
When it's full.
or
Oh wow, is it, like, dark, man?
or
Tell him the key signature has 8 sharps.
or
It's someone who knows how to play the bagpipes, but doesn't.
or
He doesn't have a heart.
or
A cow on a skateboard.
or
A slopepoke!
or
That's not a miracle. That's tapas.
or
You're Hired.
or