Groundbreaking albums. Any genre.


Not necessarily the very best but those that opened up a new direction and influenced many.
Miles Davis - Bitches Brew
John McLaughlin with Mahavishnu Orchestra - Inner Mounting Flame
Pink Floyd - Dark Side Of The Moon
Dead Can Dance - Spleen and Ideal
John McLaughlin/Paco de Lucia/Al di Meola - Friday Night in San Francisco 
Deep Purple - Machine Head
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Rush Moving Pictures
Pink Floyd The Wall
Tool Undertow (changed prog metal forever)
Yes Fragile
Led Zeppelin 1,2,4, Physical Graffiti 
King Crimson (Agree with above)
Jefferson Airplane Surrealistic Pillow
Jimi Hendrix Are You Experienced...

The list could be somewhat endless as we go through genres.
Elvis Presley-Elvis PresleyVelvet Underground & Nico-The Beatles-Sgt Pepper'sThe Who-My GenerationThe Ramones-The RamonesThe Smiths-The SmithsBlack Sabbath-Black SabbathThe Beach Boys-Pet SoundsMarvin Gaye-What's going onDavid Bowie-The rise and fall if Ziggy StardustMiles Davis-Kind if blueHerbie Hancok-Head hunters.....and many oters
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.....King Crimson-In the court,
Stevie Wonder-Songs in the key if life,
The Byrds-Fifth Dimension, 
Michael Jackson-Thriller,
Pink Floyd-DSOTM,.......

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Terry Riley’s A Rainbow in Curved Air. 
Talk Talk’s Spirit of Eden. 
Both of those changed expectations of what recorded sound should sound like.