- Elvis Presley: s/t debut. He and his band mixed black R & B with white Hillbilly, creating Rockabilly and all the Rock ’n’ Roll that followed. Buddy Holly, Carl Perkins, Jerry Lee Lewis, and others followed Presley’s lead.
- Bob Dylan: Blonde On Blonde, in which he infused Rock ’n’ Roll music with abstract surreal poetry, turning a teenage music into an adult one. IMO the most influential Pop music artist of the 20th century in the long term, more so than Elvis or The Beatles. You may disagree. ;-)
- The Byrds: Sweetheart Of The Rodeo. Chris Hillman and Gram Parsons turned the McGuinn-led Folkie group into a Country one, introducing the modern Rock audience to Hillbilly music. Hugely influential album to Rock musicians, though those of us paying attention had already began to discover Hank Williams, Lefty Frizzell, The Louvin Brothers, The Carter Family, Bill Monroe, and all the other Hillbillies Elvis and the other Southern white boys were hearing on the regional radio stations in the late-40’s and early-50’s.
- Cream: Fresh Cream. Basically a Blues band (though Jack Bruce and Ginger Baker were more Jazz influenced) who introduced long Jazz-type improvisation to the Rock audience. Whether or not that’s a good thing is a matter of opinion. After hearing The Band’s debut album Music From Big Pink, Eric Clapton himself decided it wasn’t.
- And of course The Band: Music From Big Pink. Amongst a "certain" group of young Rock-based musicians, the biggest game-changer of them all. For those who "got it", the rules of the game had been suddenly changed, the rug pulled out from underneath them. Everyone I knew had to start over, learning to approach music and it’s making in an entirely new way: Playing from the "outside" towards the center, rather than the opposite, if you know what I mean.
There are plenty more albums that can be cited, none more so than Are You Experienced by The Jimi Hendrix Experience. That band and album created a music template still imitated today, but for me the it was short-lived (I loved them the first time I saw and heard them live in ’67, but was bored the second time in ’68). It and they now sound dated to me. You may disagree. ;-)