Power pop and purity rings? From what evangelical Disney-fied wonderland did the Jonas Brothers spring? (Answer: Wyckoff, N.J.) Two of the trio have left the teen realm, but the group retains its chokehold on America's children. A reality show, concert film and hot-ticket tour (7 p.m. Saturday at the New Orleans Arena) don't jive with its third album — and second No. 1 — in 12 months: Lines, Vines and Trying Times (Hollywood). It's hard out there for an imp.