The Most Beautiful Song of The RnR era?

Thanks for the ideas, everyone.

To clarify:
R'n'R era really means music made by rock musicians. Since the idea is to debunk his notion that rock musicians haven't made any beautiful music, I thought a well selected compilation might broaden my father in law's view of "r'n'r" songwriters while allowing me to get in some contemporary music listening time during the family vacation. Though some responses went a different way (my original post was worded more generally), I'll look forward to exploring some of those suggestions for my own benefit.

Beeswing did refer to the Richard Thompson song. If my FIL is ok with RT's voice, I'm betting he'll like the song.

Fleetwood Mac- Landslide

Bruce Springsteen- Two Faces Have I

U2- One

Weezer- Island in the Sun

Dave Mason- Sad and Deep as You

Elvis Costello- Every Day I Write the Book

Graham Nash- Simple Man

Neil Young- Harvest Moon

Beatles Here Comes The Sun

Just to name a few:
"White Bird" by It's a Beautiful Day
"Yesterday" by the Beatles
"Darling Be Home Soon" by The Lovin' Spoonful
"Candles in the Rain" by Melanie
"Dust in the Wind" by Kansas
"Love Alive" by Heart
"Free Man in Paris" by Joni Mitchell
"Winter" by Tori Amos

I would not call it the "most beautiful song of the RnR era" but the running list ought to include "Killing Me Softly" by Roberta Flack.