“Georgia On My Mind” - Ray Charles
I honestly cannot believe no one has seconded this. Or even mentioned Ray Charles!
Apart from Ray (my favorite vocalist of the rock era), here are some others...
”Mr. Pitiful” - Otis Redding
”Can’t Turn You Loose” - Otis Redding
“Twist and Shout” - John Lennon
“I Am The Walrus” - John Lennon
”Kozmic Blues” - Janis Joplin
”Get it While You Can” - Janis Joplin
”To Love Somebody” - Janis Joplin
“Me and Bobby McGee” - Janis Joplin
“The Letter” (live) - Joe Cocker
”Sweet Thing” - Van Morrison
“(Your Love Keeps Lifting Me) Higher and Higher” - Jackie Wilson
Blue (album as one cohesive work) - Joni Mitchell
”White Rabbit” - Grace Slick
”Today” - Marty Balin with Grace Slick
”Levon” - Elton John
This list is not exhaustive, even of some of the artists mentioned. Just a few thoughts.