Sometime during the sessions for Between the Buttons in fall 1966, The Rolling Stones saw Jimi Hendrix play live. Hendrix was in London then, doing what would become known as doing his Jimi Hendrix thing: playing the guitar with his head, his teeth, while it was on fire, and with a general degree of power and lightness that made everyone else look mortal. The band was impressed. (Brian Jones, who was taking acid so continuously that he may have been crying for any number of reasons, reportedly emerged from one of Hendrix’s shows in tears.) Not that they shifted course. If anything, Between the Buttons was an entrenchment. Touring, which the band had spent most of the year doing, had toned their muscles. Jones’ indifference towards the guitar had mellowed into polite estrangement. Where the marimba of “Under My Thumb” had seemed striking a year earlier, Jones was now playing trumpet, vibraphone, recorder and kazoo. Charlie Watts, who until then often seemed to be drumming primarily because rock bands need drummers, became a focal point: “Connection”, “Yesterday’s Papers”, “My Obsession”—all instances where less and less (tight, primitive, often cymbal-free patterns) felt like more and more. The rhythm was there, and the soul was, too. But the white British blues that the Stones had made their name on was fading like a scar. Aftermath had introduced new kinds of ballads: part folk, part psychedelia, guided by the feel of soul but not the structure of it. “She Smiled Sweetly”, which had no guitar at all, is one. The indomitable “Ruby Tuesday”—left off the album’s UK version—was another. If Aftermath’s “I Am Waiting”—always an underrated song—proved the band could submit themselves to a woman without turning it into a power play, Between the Buttons combined that new vulnerability with a stoicism that defined the band’s ballads for years to come: wistful and bittersweet, but faced unblinkingly towards the wind. Jimi Hendrix, Eric Clapton and Cream—let the kids run with the ball. Chasing them would only wear you out. So, maturity—maybe. But confidence and self-sufficiency—definitely. At a time when even The Beatles—then between Revolver and Sgt. Pepper’s—seemed to be coming down with a case of futurism, The Rolling Stones of Between the Buttons stood firm in their moment. Still, the bite bit. When they played “Let’s Spend the Night Together” on The Ed Sullivan Show in January 1967, Jagger acquiesced to changing the lyric to “let’s spend some time together”, but not without rolling his giant eyes. Sexy was manageable. But pair it with smart and one has cause for worry.