It was 44 years ago that...


Parlaphone released the Beatles 'Sgt. Pepper's Lonely Hearts Club Band'.
What other albums can be considered having as much impact, actually altering the direction of a music genre?
montejay
One could also argue that Little Richard's "Tutti Frutti" released in 1955 impacted rock and roll much more.

Little Richard began recording in 1951, 4 years earlier than Berry.

He is widely recognized as the performer who transitioned rhythm and blues to rock and roll.
Well if you wanna play that game,Rock Around the Clock by Bill Haley and the Comets started the RocknRoll revues that started carrying the sound through out the USA. RocknRoll in the south started breaking down racial barriers in the south.
But to get back to the original posters question
Srgt. Pepper was using new ways to record @ the time,heavily influenced by drug use which was taking off in the summer of love.
Bitches Brew fused Jazz and electric instruments in a raw nervy way making most jazz musicians sit up and take notice.
Jimi Hendrix "Are you Experienced

I remember buying it the first week it was out. Used it to terrorize my parents along with The Velvet Underground.
-Hendrix Are You Experienced = Global change in electric guitar playing, (not just in rock).
-1st Velvet Underground laid down a foundation that hundreds built on, (Bowie, Roxy Music, Sonic Youth...).
-1st Black Sabbath, grudgingly must admit had a big hand in establishing metal.
-1st Van Halen, busted open another smaller door.
-Captain Beefheart, Trout Mask Replica, helped shape a wide range of punkers, outside rockers and jazzers who were looking to push the edge.
-Sex Pistols Nevermind the Bollocks, 1st Cars and Nirvana Nevermind showed that there was still some flavor left in what appeared to be stale chewing gum.