Chris Willman Music Writer“American Idol” has set no fewer than a dozen music stars for the series’ grand finale May 23 — three of whom may be fairly predictable, given that Luke Bryan, Lionel Richie and Katy Perry are the show’s judges.Not quite as foreseeable in the final show’s performing pecking order: Sheryl Crow, Chaka Khan, Luke Combs, Mickey Guyton, Lindsey Buckingham, Fall Out Boy, Alessia Cara, Leona Lewis and Macklemore.The show will air on ABC live across time zones May 23 at 8 p.m.