What are the 2 quintessential albums of all popular music eras/genres?

Punk rock (70s) Sex Pistols: Never Mind the Bollocks Ramones: Ramones Noise rock (80s) Sonic Youth: Sister The Jesus & Mary Chain: Psychocandy Ambient Electronica (90s) Aphex Twin: Selected Ambient Works vol. 2 (not a compilation, despite the title) Biosphere: Substrata Shoegazer rock (around 1990) My Bloody Valentine: Loveless Lush: Scar (mini-album)

Before 1950: Blues-  Gotta be the Robert Johnson's recordings from the mid thirties.  These have been packaged and repackaged many times in singles collections. Jazz-  Rainbow Mist (1944) from Coleman Hawkins.  Mr. Hawkins broke the ground that later sax players sprang from. Country-  Dust Bowl Ballads (1940) by Woody Guthrie. The '50's: Blues-  The Best Of Muddy Waters (1958) was the Mudcat's first album.  It was a collection of his previous singles from the late '40's through the '50's.  He was the most important artist in the genre during the decade. Jazz-  This is a tough one.  I'll go with Miles Davis' (1959) Kind of Blue.  There's a ton of other good candidates though. Rock-  I'm going to have to go with Elvis' Sun Sessions which produced his self-titled first album. Country-  Hank Williams' Moanin' The Blues (1952). The '60's- Blues-  Blues Breakers (1966) by John Mayall.  This is the album that broke blues as a commercially viable musical form for British, then American, youth. Jazz-  From Lee Morgan we got The Sidewinder in 1964.  It is the quintessential Blue Note album of the decade. Rock-  The most influential Rock album of the '60's has got to be Sgt. Peppers.  It's not my favorite Beatles album, that would be Revolver, but in its time Pepper was the ground-breaker. Country-  I Walk The Line from the Man In Black, big Johnny Cash. The '70's-  Blues-  The London Howlin' Wolf Sessions (1971).  Youth meets up with a sturdy blues veteran.  Clapton, members of The Stones, back up Wolf on some smokin' tracks. Jazz-  Ornette Coleman's Dancing In Your Head (1975) took Jazz into a new domain.  Still ahead of its time. Rock-  Europe '72 from The Grateful Dead maybe the most beautifully recorded live album of all time. Country-  Lucinda Williams' self-titled debut is bluesy country at its best (1979). I'll think about the next three decades.

Swedish avant-rock: Pärson Sound - Pärson Sound Samla Mammas Manna - Måltid Ukrainian ethereal folk: Cukor Bila Smert' - Manirna Muzika Svitlana Nianio & Oleksandr Yurchenko - Знаєш як, розкажи Poezja śpiewana: Ewa Demarczyk - Ewa Demarczyk śpiewa piosenki Zygmunta Koniecznego Marek Grechuta - Korowód Latvian minimal synth: NSRD - Medicīna un māksla t.u.m.s.a. - Veltījums tumsā Norwegian post-punk: The Aller Værste! - Materialtretthet De Press - Block to Block (My point here is that for this concept to work at all you can only mention niché genres. There are hardly any big genres where you can name two 'quintessential' albums. There will almost always be more than just two, unless you are talking about genres such as shoegaze, where Loveless is the undisputed classic, or chopped & screwed, where DJ Screw's records reign supreme).

Imho Tago Mago and Ege Bamyasi by Can, and Neu! by Neu! simply anticipate almost any latter musical style, but pop and rap. Here you can find the sounds that inspired New Wave, punk, post punk, post rock or whatever. These are the sounds that influenced so called "innovative artists" like PIL, Joy Division, but also Radiohead, Sygur Ros,  Beck and so on.