Query: When did American Idol showcase a new set and stage?
Context: For the finals, American Idol debuted a new state-of-the-art set and stage on March 11, 2008, along with a new on-air look. David Cook's performance of "Billie Jean" on top-ten night was lauded by the judges, but provoked controversy when they apparently mistook the Chris Cornell arrangement to be David Cook's own even though the performance was introduced as Cornell's version.