Rowlf is a
dog. He played
piano on
The Muppet Show in both the
pit orchestra and on stage (either
solo or as
accompaniment). He did not play with the
Electric Mayhem. His piano was slightly out of tune,
reminiscent of
ragtime pianos. One of his most famous performances was of "I've Never Harmed an Onion, So Why do They Make Me Cry?" In
The Muppet Movie, he sang (and played) a duet with
Kermit the Frog called "I Hope That Something Better Comes Along". Has an
album, released in
1993:
Ol' Brown Ears is Back.
Rowlf was voiced by Jim Henson, and was performed by Henson and (usually) Frank Oz. Two performers were necessary -- one for the head and one for both hands. No one has voiced Rowlf since Henson's death, despite his apparent popularity. This is too bad.
Rowlf is probably the second-oldest Muppet still in use today, behind only Kermit. He appeared in commercials for Purina dog chow, and he made regular appearances on the Jimmy Dean Show (as well as occassional appearances on some other variety shows). According to Henson.com, he was also a spokesdog for IBM at one point.