Flashback: See Glen Campbell Sing Allen Toussaint's 'Southern Nights'

Glen Campbell will be forever linked to songwriter Jimmy Webb, who provided the Rhinestone Cowboy with signature hits like “By the Time I Get to Phoenix,” “Wichita Lineman” and “Galveston.” But it was Allen Toussaint, the legendary New Orleans musician who died earlier this week at 77 after suffering a heart…