Warren Zevon
Zevon sometimes recorded or sang cover songs.  He liked to sing Bob Dylan's "Knockin' on Heaven's Door" and Leonard Cohen's "First We Take Manhattan". He was often a guest on Late Night with David Letterman and the Late Show with David Letterman. Letterman later sang with Zevon on "Hit Somebody! (The Hockey Song)" with Paul Shaffer and members of the CBS Orchestra.