"It's about having a hard time and getting out. Just a metaphor for getting out of all the acid things," Jagger told Rolling Stone's Jann S. Wenner in 1995. After the psychedelic experimentation of Their Satanic Majesties Request, "Jumpin' Jack Flash," released in May 1968, was a primal system shock that kick-started the greatest period in the band's career. Richards was on a historic run at the time, exploring the open-D blues-guitar tuning for the first time and coming up with some of his most dynamic riffs. He overheard an organ lick that bassist Wyman was fooling around with in a London studio and turned it into the song's unstoppable, churning pulse. The lyric was inspired by Richards' gardener, Jack Dyer, who slogged past as the guitarist and Jagger were coming to the end of an all-night session. "Who's that?" Jagger asked. "Jumpin' Jack," Richards answered. The song evolved into supernatural Delta blues by way of Swinging London.