Even more so than the Beatles' early catalog, the Rolling Stones' first few albums looked quite different when they made it to U.S. fans. By the time The Rolling Stones, Now! was released on Feb. 13, 1965, two other records by the group were already available: England's Newest Hitmakers, which was released in May 1964, and 12 x 5 from October 1964.

Back in their homeland, however, the Stones had only two albums in stores: The Rolling Stones from April 1964, and The Rolling Stones No. 2, which was released a month before The Rolling Stones, Now! And things got messy rather quickly, with songs left off of this album, added to this one or just completely reworked from one edition to the next.

Only seven of the 12 tracks on Now! were repeated from The Rolling Stones No. 2, with various singles, leftover songs from the U.K. debut – and even a song that wouldn't be released in the Stones' home until seven months later filling in the gaps.

The result? The group's first essential U.S. album.

While it's not so far removed stylistically from its two predecessors – the majority of the songs are covers by the blues and R&B giants the Stones worshiped – The Rolling Stones, Now! is a huge leap forward for the band. In addition to writing their own songs (Mick Jagger and Keith Richards' "Heart of Stone" is the best of them), they were playing tougher, tighter and with more determination than before.

Listen to the Rolling Stones Perform 'Little Red Rooster'

Their cover of Willie Dixon's blues standard "Little Red Rooster" (made famous by Howlin' Wolf just four years earlier) may be the Stones' greatest stab at the genre. Guided by Brian Jones' wailing slide guitar, the group comes the closest it ever did, in both punchiness and allegiance, to replicating the American music they loved. (Jones also contributes the blazing harmonica solo that closes the song.) And "What a Shame," a Jagger-Richards carryover from The Rolling Stones No. 2, applies their blues lessons to an original that sounds remarkably like the real thing.

While 12 x 5 charted higher (reaching No. 3; their follow-up made it to No. 5), The Rolling Stones, Now! is the better album, a setup of sorts for Out of Our Heads, the first of the Stones' nine No. 1 LPs and the first to include more original compositions than covers. And the first real firing shot of their legend.

They were still a few years – literally and symbolically – away from a late-decade string of masterpieces that carried them into the '70s and made them one of the biggest bands on the planet. But The Rolling Stones, Now! proved that they weren't just another British group playing around with American music.

It lives, it breathes and it pulses. They feel it here. And so can you.

20 Altered Album Covers

Altered album covers must have a resume topped by at least one offense – be that death, nudity and general ickiness.

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