Siri is the intelligent personal assistant of Apple's devices to help you get things done.
Siri can help you send messages, place calls make dinner reservations and more. However, though designed to be intelligent and interactive, there are still questions and request that Siri won't do.
One of them is to make Siri sing. Siri would reply it can't sing and would rather leave it to the professionals.
So when this guy wanted to have a beat-box collab with Siri, he needed to trick her and ask her a question that would have her do some beat-boxing and the result is pretty amazing.
Check the video out.