Coming from Harlem where his poppa was a preacher at Abyssinian Baptist Church, pianist Fats Waller wasn’t no angel. A p.k. who ran around town misbehavin’ with his cocktail-sipping crew, Waller also swung with a few Vipers.

For those not hip to the daddy-o slang of the golden years of the 1920s, “Viper” was a slick name for a pothead. In a revealing 1971 tape recording with Waller contemporary Louis Armstrong—who himself was arrested for pot possession forty years before—Satchmo says “we did call ourselves Vipers, which could have been anybody from all walks of life that smoked and respected gage. That was our cute little name for marijuana, and it was a misdemeanor in those days.”

“If You’re a Viper,” a jazz song dedicated to “loco-weed” heads, was written by Stuff Smith, who released his own version in 1936. Smith’s song detailed his dream “about a reefer five foot long, might mezz, but not too strong,” which excited those who were down with slang.

When Waller covered the song seven years later, he made it his own. The popular standard was included in Ain’t Misbehavin’, a musical constructed around the big man’s swinging music. A few years ago American Idol winner Ruben Studdard toured with the show, playing “Viper” every night.