The Beagles

The Beagles was a Saturday morning cartoon from the creators of Underdog. It ran for one season (1966-67) on CBS. From the Toon Tracker page:

The Beagles featured a singing and guitar-playing canine duo known as Stringer and Tubby. The dog stars of the series worked catchy, British-Invasion style rock n' roll songs into the action of each episode. Before a new number joined the duo's repertoire, their manager placed them in an exciting situation where they could experience what the song was all about. Each week the performing pooches were put through their paces, all for the sake of their rock n' roll art! Presented on CBS-TV in serialized adventures, The Beagles were an obvious attempt to cash in on the sound-alike name of the Fab Four from Liverpool, who began their own show the year before on ABC-TV. When The Beagles series failed to generate high ratings, it was cancelled by CBS. It was repeated the following season on ABC before it quickly disappeared.

This series provides examples of:
 * Fat and Skinny: Reflected in their names and instruments of choice. Stringer was a guitarist and Tubby was a bassist.
 * Follow the Leader
 * Too Good to Last