根据短文内容, 回答问题。

A Concert

    The Newtown School will have a concert on Children's Day. Ann, Ken and David will play together in the concert. Ann will play the piano, Ken will play the guitar, and David will play the drums. Mocky will not play in the concert, but he will go, too.

    All the children and their parents are at the concert, but David will not be there because he is not well today. Who will play the drums? Ken and Anil are worried. But Mocky can play the drums. Believe it or not, he can play really well.