Good things really do come in threes now and then. Case in point: Thursday’s late-night talk show musical guests The first good thing: A bearded, big-scarfed Rufus Wainwright, who debuted his powerful political piano ballad Sword of Damocles for The Late Late Show with James Corden. The second: Popster Bebe Rexha, who brought some rock — and plenty of dry ice — to Jimmy Kimmel Live with her performance of the single I’m A Mess, from her album Expectations. And finally: New Orleans roots-rockers The Revivalists, who showcased the soulful Take Good Care on The Late Show with Stephen Colbert. Enjoy your weekend. Pity it isn’t three days long.