"One Toke Over the Line" by Brewer and Shipley.

OK, boys and girls, more 70s one-hit wonders: These two L.A.-based folk singers relocated to Kansas City and became the house act at the Vanguard Coffee Shop. One night in '71 between sets in their dressing room, bored and more stoned than usual, within one hour they penned this Country-Rock classic which became their only hit. #10 Billboard, #8 Cash Box. At one point they became the opening act for Melanie. Quoting one of the co-authors, "I considered marijuana a sort of a sacrament. It's a song about excess. Too much of anything will probably kill you". The FCC issued a warning to radio stations regarding playing songs about "the benefits or dangers of drug abuse". Some stations stopped playing it whereas others played it even more often in protest. Part of the "Fear and Loathing in Las Vegas" and "St. Vincent" movie soundtracks. Folk singers Gail Farrell and Dick Dale (from Algona, Iowa - the singer, not the guitarist) sang it on The Lawrence Welk Show, introduced as "a modern spiritual (!)". Neither Welk nor the performers had any idea that the tune was about marijuana, not Jesus! Song? Duo? Answer: "One Toke Over the Line" by Brewer and Shipley. https://www.youtube.com/watch?v=L9HXClusp_E https://www.youtube.com/watch?v=t8tdmaEhMHE