Which Muppet character is a dog who plays the piano?

The Muppet character who is a dog and plays the piano is Rowlf the Dog.

Rowlf is an anthropomorphic, scruffy brown dog known for his relaxed manner, deadpan humor, and musical ability. On The Muppet Show, he is the resident pianist, accompanying the house band and appearing in musical numbers. He also plays Dr. Bob in the recurring sketch “Veterinarian’s Hospital,” alongside Miss Piggy and Janice.

Jim Henson created and originally performed Rowlf. The character first appeared in Purina Dog Chow commercials in 1962, making him one of the earliest Muppets to achieve public recognition. Rowlf later became a regular on The Jimmy Dean Show from 1963 to 1966, which made him the first Muppet to appear regularly on network television.

Waldorf and Statler are not musicians in the same sense: they are the elderly balcony hecklers who criticize the show. Scooter is the backstage stage manager, while Rowlf is the dog associated with the piano. Rowlf’s musical role is therefore the defining clue in this question.