If I can just pick a nit…Do bands like the Ramones actually define the 1970s? Even the music they actually recorded in the 1970s sounds like it’s from a different decade. That was the whole point of the Ramones (and other Punk bands like the Pistols); to NOT sound like Seventies music.
That’s all true, so the irony was that punk rock that wanted to sound nothing like all the dinosaur/prog bands mentioned in this thread, itself became one of the defining sounds of the seventies.
The antithesis can’t keep itself from becoming part of the synthesis.
And thr guy who is playing the guitar is Stephen Bishop, himself a wussy singer songwriter. “On and On” is probably his beat known song.
Yeah - but that just points out the difficulty of considering decades to be meaningful in terms of music, or that any one musical style “defines” a decade. MAYBE you’d want to identify groups/albums that had the most success for the longest period within a decade. So do you include Zepplin, when I and II were recorded in the 60s? How about Deep Purple, whose best music was before 75?
Foreigner (to me) seems VERY 70s - but their debut was in 78.
Has Steve Miller Band Book of Dreams been mentioned yet?
one not named yet, but Chicago VII – so eclectic and great.
Some of the above, while released in the 70’s are sort of timeless. A young person today might listen to and like Neil’s Rust Never Sleeps, but it might not scream 70’s to them. Same for Zep and the Eagles. Regarding the OP, some rock albums are frozen in the 70’s, imo.
Uriah Heep - The Magician’s Birthday is one such album.
“Fly Like an Eagle” is much more a quintessential 70’s album.
We should add ZZ-Top to the mix. My favorite of theirs from the 70’s is Deguello, but Tres Hombres works too.
Then there was the whole genre of southern rock/Country rock, consisting of:
Eagles
Poco
Allman Brothers
Atlanta Rhythm Section
Marshall Tucker Band
Outlaws
Lynyrd Skynyrd
Skynyrd has already been mentioned, and I think the Allmans (I’d pick “Live from Fillmore East”).
Then there were the ‘Outlaw Country’ folks that made it big in pop radio in the 70’s. Waylon Jennings, Willie Nelson, Tompall Glaser, Jessi Coulter, Merl Haggard, etc. The album I would pick from them would be “Wanted: The Outlaws”. The album is full of radio hits and still gets lots of play today. It was the first platinum country album.
Carole King / Tapestry
Linda Rondstadt
Jefferson Airplane
Defining sixties band for me.
Right. Starship then 
you all forgot THE man that stands more for the 70ies than most mentioned above:
.
.
.
Bob Seeger!
- turn the page
- nutbush city limits
- night moves
- mainstreet
- still the same
- hollywood nights
- we got tonight
- old time RnR
- Fire lake
- Against the wind
all from '71-80
it’s not just that they were HITs, but I feel also hits that transported the 1970ies feeling really well … and you cant be more american than bob seegers americana!
What I’ve Learned From This Thread:
- The early, mid and late '70s are different eras, and came at different times of our lives.
- My '70s and your '70s are not the same.
- Opel would just shrug.
Come to think of it, my “Allman Bros. and Poco and the Dead” '70s are so different from my “Figuring out Cohen and Dylan lyrics” '70s, or my “Spirit and King Crimson and Genesis-But-The-One-With-Peter-Gabriel-Doing-Cosplay” days.
Did you forget someone whose initials are “GP?”
Gram Parsons? Hugely influential, but did he have a ‘quintessential 70’s album’?
I was thinking of Stevie Ray Vaughan as well, but I don’t think he really had a single iconic album.
Did anyone mention Meat Loaf - Bat out of Hell? That has to be one of the most iconic 70’s albums. It was everywhere.
I suppose not. But he was arguably the godfather of country rock.
Definitely a major influence.
Oddly, I saw both Foreigner and Steve Miller Band live in concert last year. Both advertised as their farewell tour.
Third, Forth or Fifth?