Fiddler and Keys are two musician cats, with Fiddler playing the violin and Keys playing piano. When they appear they are usually talking about music-related things or doing a musical number. They are a couple and also a resource for musical jokes in the story. They are usually shown together, but each made a solo apperance once. Fiddler in Hey, It’s That Cat Again and Keys in First Things First. In a couple of one-shot strips, the duo has performed their own song compositions.