From Yahoo News:
“Washington – Whether you loved or hated the classical music played at President Barack Obama’s inauguration, unless you were sitting within earshot of the celebrated quartet, what you heard was a recording made two days earlier.”

“They were very insistent on playing live until it became clear that it would be too cold,” said Florman in a telephone interview Thursday night.”

Yeah, I don’t blame them at all. It was a great John Williams arrangement though. Here is the actual performance.