I can't argue with you, Karen Carpenter's voice is top notch. Two more I'll recommend, nothing to do with the seventies but so what:
Patsy Cline - "She's Got You" and Willie Nelson's "Crazy"
Sinead O'Connor - Prince's "Nothing Compares 2 U"
Yes, "Tapestry" was a masterpiece. "Will You Love Me Tomorrow?" tops it.
"In a Broken Dream" is one of Rod's best, equal to "Maggie May."
The Hollies, need I say more?
Trust me, I'm a doctor.