Scooby-Doo the series and the billing, in an attempt to boost "Scooby-Doo"s slipping ratings. The 1979–80 episodes, aired under the new title "Scooby-Doo and Scrappy-Doo" as an independent half-hour show, succeeded in regenerating interest in the show. Lennie Weinrib voiced Scrappy in the 1979–80 episodes, with Don Messick assuming the role thereafter. Marla Frumkin replaced Pat Stevens as the voice of Velma mid-season. As a result of "Scooby-Doo and Scrappy-Doo's" success, the entire show was overhauled in 1980 to focus more upon Scrappy-Doo. At this time, Scooby-Doo started to walk and run anthropomorphically on two feet more often, rather than on
Scooby-Doo, Where Are You! Roberts, and were performed by Roberts, who also made a new recording of the "Scooby Doo, Where Are You!" theme song for the second season. The series' theme song has been covered by several subsequent artists, including Matthew Sweet for the 1995 TV special and album ""; Third Eye Blind for the 1998 film "Scooby-Doo on Zombie Island"; Billy Ray Cyrus for "Scooby-Doo! and the Witch's Ghost" (1999); Jennifer Love Hewitt for "Scooby-Doo and the Alien Invaders" (2000); the B-52's (Cindy, Kate and Fred) for "Scooby-Doo and the Cyber Chase" (2001); MxPx for the live-action "Scooby-Doo" film (2002); and Krystal