It turns out “Take Back the Night,†the first single off the sequel to Justin Timberlake’s 20/20 Experience, is not an anthem for the well-known campaign to end sexual violence. It is a song about dancing (and then getting it on). But as far as getting-it-on dancing songs go, it’s a solid one, with a heavy disco vibe and the all-important handclaps. (Quick: Name a bad song that uses handclaps. You can’t!) Really the only quibble here is that Justin Timberlake still refuses to make a song under six minutes, which is fine; a radio edit should be out soon enough.