The instant success of country-pop trio Lady Antebellum should serve as a lesson in Mass Marketing 101. The recipe is seamless: Take two men and one woman, make sure they're photogenic, have them harmonize just enough, gather simple, radio-ready tunes and then promote them incessantly. Whiz bang! We got ourselves a winner! Charles Kelley, Hillary Scott and Dave Haywood performed tonight as this year's first headliners on the Chevrolet Main Stage at the State Fair of Texas in Fair Park. Backed by a three-piece band, the group offered all 11 tracks on its self-titled debut CD and a few covers, including the most tepid rendition of AC/DC's "You Shook Me All Night Long" ever attempted. Not that their material sounds much better. With few exceptions the cuts on that disc are generic and passionless. For a full review of Lady Antebellum check out www.guidelive.com Saturday afternoon or Sunday's GuideLive section. Photo: Lady Antebellum in a publicity shot -- Charles Kelley, Hillary Scott and Dave Haywood (Mark Humphrey). ...