<P> The show's team of producers included Robert L. Jacks, Gary Adelson, Greg Strangis, and Phil Fehrle . Executive producers were Lee Rich and Philip Capice . </P> <P> As a production of the Lorimar stable, who were concurrently producing CBS's The Waltons, writers were often contracted by the producers and were shared between both programs . (Waltons costar Will Geer also made an Eight is Enough guest appearance during season 2 .) Regular writers included Peter Lefcourt, the writing teams of Gwen Bagni and Paul Dubov, Rod Peterson and Claire Whittaker, Bill Nuss and Dusty Kay, Nick Thiel and David Braff, J. Miyoko Hensley and Steven Hensley, Bruce Shelly, Sandra Kay Siegel, Gil Grant, Karen I. Hall, and Hindi Brooks, who soon became the show's long - time story editor . In - house directors included Philip Leacock, Harry Harris, and Irving J. Moore . As an in - joke, the character name of one of Nicholas Bradford's best friends was Irving Julius Moore, a nod to the director of the same name whose middle name was in fact Joseph . </P> <P> For the show's first two seasons, an upbeat instrumental piece written by Fred Werner was used as the show's opening theme . Beginning with the show's third season, this was replaced by a slowed - down vocal theme titled "Eight Is Enough," which was sung by series co-star Grant Goodeve . The song had music by Lee Holdridge and lyrics by Molly - Ann Leikin, and was first heard in a longer arrangement on the last episode of the second season titled "Who's on First?", which was also performed by Goodeve . </P> <P> Early episodes had instrumental music by Fred Werner and the prolific Alexander Courage, but the show's real musical stamp came from veteran composer Earle Hagen, who had a knack of composing memorable cues as he had previously been the in - house composer on The Andy Griffith Show . He composed a love theme for Tom and Abby, a theme that permeated the show in various incarnations throughout the remainder of the series . Some later episodes were scored by John Beal and Miles Goodman . </P>

Who sang the eight is enough theme song