My children and I have been watching a wonderful new show on the Noggin cable channel called "Jack's Big Music Show."
It's a puppet show for pre-schoolers designed to get them interested in music. Each episode features different musical genres, instruments, etc.
The two main puppets are named Jack and Mary! On one episode, a magician accidentally turned Jack into a bunny -- Jack Bunny.
They are often interrupted by a puppet singing group called the Schwartzman Quartet who enter a room by singing "Hmmmm!"
Someone in production over at Noggin/Nickelodeon Studios must be a big Jack Benny fan!