Last night’s Parks and Recreation season finale built up to the Unity Concert, which was closed out by Andy’s band Mouse Rat, with very special guests Jeff Tweedy (as Land Ho! frontman Scott Tanner), Yo La Tengo (playing Bobby Knight Ranger—hence their Indiana-appropriate Bobby Knight outfits), the beloved and long-ago-disbanded Letters to Cleo, Ginuwine, the Decemberists, and more.

Together, they sang a moving tribute to Li’l Sebastian, the late mini-horse, who made an unexpected appearance of sorts. That song is above, and you can watch the whole episode below.