"Oh my god, get away! No one likes you!"

Jake is slightly too panicked by the attempted divebomb to sing. No weapon! And he obviously can't punch a bird. What on earth is a defenseless singing jester to do?

Scream, of course. He lets out a single scream as he plays as loudly as he can, discordant notes rising faster and faster. And if that fails, Plan B is trying to catch a bird with a banjo.