How do I play the haunting song?

The correct sequence is:

•↑→•↓•↓→

(That means hit Z, Z-Up, Z-right, Z, Z-down, Z, Z-down, Z-right.)

Actually, it gives you the answer if you wait, in a dialog text with the statue. The only thing you need to do is memorize that.

EDIT: Turns out you don't have to be in dialog.