It’s easy to be an Al Green fan: you just have to have ears. David Letterman counts himself among the Al Green faithful, and after the two met and exchanged pleasantries at the Kennedy Center Honors last week, Letterman decided to have Green on The Late Show apropos of nothing. Having no new music to promote, Green instead treated the audience to a few classics with a medley of “Tired Of Being Alone” and the too-classic-for-words “Let’s Stay Together.” You can watch the full, stunning performance below: