Here's some '70's from the emerging country-rock scene in Los Angeles... ( some mellow, some not)
The Eagles
Gram Parsons
Loggins and Messina
Poco
Crosby, Stills, Nash and Young
Ricky Nelson - Garden Party, etc
Flying Burrito Bros.
Linda Ronstadt
The Byrds
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and then other genres... and other places...
Willie Nelson
Paul Simon - Paul Simon '72 and There Goes Rhymin' Simon '73
Stevie Wonder - Music of My Mind '72, Talking Book '72, Innervisions '73, Songs in the Key of Life '76
Bob Dylan - Blood on the Tracks
Laura Nyro
Carole King
Joni Mitchell
Elton John
from a middle age old fart...