One Toke Over The Line, Lawrence Welk, 1971

Later: I have to add this from Wikipedia:

"One Toke Over The Line"[written by Mike Brewer and Tom Shipley] was performed on The Lawrence Welk Show, a television program known for its conservative, family-oriented format, by a duo known as "Gail and Dale." At the conclusion of the performance of the song, Welk remarked, without any hint of irony, "There you've heard a modern spiritual by Gail and Dale." 

This caused Michael Brewer to comment:

"The Vice President of the United States, Spiro Agnew, named us personally as subversive to American youth, but at exactly the same time Lawrence Welk performed the crazy thing and introduced it as a gospel song. That shows how absurd it really is. Of course, we got more publicity than we could have paid for."