Norman Lear originally planned for all of the dialogue on the show to be improvised as Martin Mull and Fred Willard are skilled improvisational comedians. But head writer Alan Thicke insisted that the show would be better scripted with Mull and Willard improvising occasionally. Lear threatened to fire Thicke after the first week of shows but because of the audience's positive response, Lear relented.
The members of the Mirth Makers were usually uncredited. They were Eddie Robertson as Eddie Thomerson, bass; Tommy Tedesco as Tommy Marinucci, guitar; Frank Marocco as Frankie Carbone, accordion; and Colin Bailey as the drummer. Bailey is the only member of the band who was not featured separately in a comedic bit.