The show’s production values are unusually high for a casino residency, often calling to mind the golden age of music videos. The young-for-Vegas crowd was there for the danceable hits and the spectacle, which included acrobatics, a ring of fire, confetti, a live band, frenetic costume changes and a frequently airborne Spears. The debut of Spears’ long-term casino gig Friday kept an audience of about 4,500 on their feet for 90 minutes. LAS VEGAS (AP) - Britney Spears has begun her early retirement in Las Vegas with a show that looks strikingly like the eye-popping Cirque du Soleil productions found elsewhere on the Strip.