WHN geared up in The Music Meister's garb from the utterley fantasic episode of Batman: The Brave and the Bold where the afformentioned villain controls people's minds by singing musical numbers. It's basically a 24 munite aimated splashy musical with lots of punching and bat-puns.

The first song is here - http://www.youtube.com/watch?v=wPnqds02lFY&feature=related

You can watch the entire episode here - http://www.youtube.com/watch?v=j_OpntXZiY8&feature=related