BEFORE "NIGHT" FALLS: Justin Timberlake is such a tease. Just look at how he toys with us here, just as he did with "Suit & Tie" earlier this year, offering a tantalizing snippet of "Take Back the Night," the first single from the forthcoming 20/20 Experience Part 2. The track's arrival dovetails neatly with the Legends of the Summer tour, which Justin is about to launch with Jay-Z via Live Nation. The sequel to his chart-topping RCA album is due out in September, just in time for Grammy consideration. Wonder what he'll wear to the ceremony? (7/10p)