LOS ANGELES (AP) - Britney Spears' manager is shooting down rumors that she will lip-sync her entire Las Vegas show. Larry Rudolph tells Billboard Spears will sing live and she's been working on her choreography and vocal coaching every day. That's not to say she won't have a bit of help. Rudolph says there may be some numbers where Spears is full-out dancing with a vocal track underneath her, but "there won't be any lip-syncing across the board on anything." Rudolph says there's not a single artist out there who does full choreography and sings without a vocal track. Spears' Las Vegas residency begins December 27.