A lot of the greats already listed. I’ll add Brian Wilson, Chuck Berry, Dave Bartholomew, Pomus/Shuman, Leiber/Stoller, Willie Dixon, Buddy Holly, Hank Williams, Merle Haggard, Randy Newman, Jackson Browne, Iris Dement, John Hiatt, Rodney Crowell, Felice & Boudleaux Bryant, Goffin/King, Greenwich/Barry, Mann/Weil, and Holland/Dozier/Holland (writers of the sublime "What Becomes Of The Broken Hearted").