"Happy Trails" is a song by Roy Rogers and wife Dale Evans, known as the theme song for the 1940s and 1950s radio program and the 1950s television show in which they starred. It was written by Evans and always sung by the duo over the end credits of those programs. This keyboard lesson is about key signatures and eighth notes in the EZ-Play Today songbook by Hal Leonard. Source: Wikipedia. Thank you for watching.