Question: who sings the theme song from happy days

title: Happy Days (TV theme)
text: The song was first recorded in 1974 by Jim Haas with a group of other session singers for the first two seasons . These versions of the song were used only during the closing credits of Seasons 1 and 2 , with an updated version of `` Rock Around the Clock '' by Bill Haley and His Comets used as the opening theme . The song was re-recorded in 1975 with different lyrics for both the opening and closing credits for Seasons 3 through 10 . Pratt & McClain released the song as a single in 1976 from their album Pratt & McClain Featuring Happy Days . Bobby Arvon recorded an updated version of the song in 1983 for the opening and closing credits of Season 11 , with the same lyrics as the version used for seasons 3 - 10 . 

Answer: answer: For the first two seasons the song was recorded in 1974 by Jim Haas with a group of other session singers.
In 1983 Bobby Arvon recorded an updated version of the song for the opening and closing credits of Season 11 , with the same lyrics as the version used for seasons 3 - 10 .
answer: For the first two seasons the song was recorded in 1974 by Jim Haas with a group of other session singers and was used only during the closing credits. An updated version of `` Rock Around the Clock '' by Bill Haley and His Comets was used as the opening theme. In 1983 Bobby Arvon recorded an updated version of the song for the opening and closing credits of Season 11, with the same lyrics as the version used for seasons 3 - 10.