Here are some artists from the song list:

Elvis Presley
John Denver
Frank Sinatra
Credence Clearwater Revival
Simon & Garfunkel
Arlo Guthrie
Neil Diamond
Kenny Loggins
Bread
Eva Cassidy
James Taylor
Johnny Cash
Lady Antebellum
Green Day
Jim Croce
Beatles
Fleetwood Mac
Eric Clapton
Dan Fogelberg
Pat Boone
Cat Stevens
The Byrds
Willie Nelson
Glen Campbell
Elton John
Bobby Vinton
The Bee Gees
The Band
Louis Armstrong

…and many more