The on-stage squabbling that has been the basis of the Smothers Brothers' appeal for 30 years isn't an act, the brothers insist.

"Sometimes, we have an argument right on stage and people don't know it. They think it's part of the act," Dick Smothers said in the Nov. 19 issue of TV Guide Magazine.Dick and Tom Smothers, who began performing as a folk-singing team when they were students at San Diego State University 30 years ago, are appearing in a series of six specials on CBS this season.

Tom, 51, plays the sly, but childlike, brother on stage. Dick, 50, said Tom "is a meticulous taskmaster."

"Dickie would never be in show business if I hadn't needed a singer," said Tom.