Backstreet's back — again — all right! On Friday morning, the guys of Backstreet Boys announced additional US tour dates for their In a World Like This tour, saying they'll be joined by Avril Lavigne for the upcoming shows starting in May (2004, is that you?). Tickets go on sale starting March 20, so in anticipation of the tour's US return, we're taking a look at what, exactly, makes a BSB show so great. Behold — a recipe for the perfect Backstreet Boys concert.