Some suggestions from older material - I don't know if you're limiting your selections in any way.

"Blackbird" "Yesterday" "Rocky Raccoon" Beatles
"As Tears Go By" Rolling Stones
"Tears In Heaven" Clapton
"Dust in the Wind" Kansas (leave out the instrumental)

Simon & Garfunkel, James Taylor, Jim Croce among many others can provide material. I know this stuff is ancient but hope it helps.