There's a moment in almost every legendary act's career that marks the period in which they transcend the merely good and become truly great. Aftermath is the Rolling Stones' moment.

The band's fourth U.K. album (and sixth in the U.S.) was released not even seven months after the band's previous record, Out of Our Heads, but the leap was more monumental than the brief period between them lets on. For starters, the Stones were still singing other people's songs on the earlier record. By the time they put out Aftermath on April 15, 1966, Mick Jagger and Keith Richards were writing all of the band's songs.

But it's not just that. The songs are bigger and bolder. They take more risks, wandering outside of the blues and R&B parameters that steadied the band during its first three years. And for the first time, a Rolling Stones album plays like one – an LP crafted to come together as a total listening experience (and a long one at that: The British version of Aftermath runs 53 minutes).

The album was made during a handful of sessions in Hollywood in early December 1965 and early March 1966. It was the group's first LP to be recorded entirely in the U.S., and the first in which Brian Jones played around with a variety of instruments not exactly known for their use in rock music: dulcimer, marimba, sitar and koto, a traditional Japanese stringed instrument, among them.

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It opened up the band's sound and gave Aftermath a jolt of respectability, a wordly turn away from the amped-up versions of American blues and soul music they were best known for. Songs like "Mother's Little Helper," "Lady Jane," "Under My Thumb" and "Out of Time" were their most adventurous to date, and the exotic, sometimes haunting atmosphere they produced helped usher in the gravity that steered rock music toward more serious paths over the next couple of years. (The U.S. edition, which came out in June, omitted some songs and made room for "Paint It, Black," a No. 1 hit in both the States and the U.K.)

Like other notable albums from 1966 – particularly the Beach Boys' Pet Sounds, the Beatles' Revolver, Bob Dylan's Blonde on Blonde and the Who's A Quick OneAftermath was a pivotal moment in both the artist's career as well as an advancement for rock 'n' roll in general. The Stones' record arrived before all of them, signaling a turning point in the future direction of popular music.

Fans were on board with the move. The album hit No. 1 in the U.K. and climbed to No. 2 in the States when it was released a couple months later. In addition to the U.S.-only "Paint It, Black," "Mother's Little Helper" and "Lady Jane" were issued as singles. The former made it to the Top 10 in the U.S., while the decidedly more challenging "Lady Jane" (which included only Jagger on vocals, Richards on acoustic guitar, Jones on dulcimer and Jack Nitzsche on harpsichord) stalled outside the Top 20.

But Aftermath heralded a brave new world for the Stones. Their next album, Between the Buttons – which didn't arrive until the start of 1967 – was a continuation of the group's restless creativity as the rest of pop culture prepared for the Summer of Love. Right around the corner from that was Beggars Banquet, Let It Bleed and then, eventually, world domination.

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