If, like me, you thought there was something a little off with the performance of John Williams's Oscar-grabbing inauguration theme, you were right. What we heard was a recording made two days prior.
Due to January 20' "wicked cold" (Mr. Ma's words), the inaugural planners decided to roll tape for "Air and Simple Gifts" with the intent of avoiding frozen fingers or rapid de-tunings causing a John-Roberts-scale fuckup on the world stage.
I can't say that I blame them at all. Itzhak is getting up there in the years, and he's earned a bit of slack. Apparently inaugural tunes are always pre-recorded to avoid just such a mishap; interesting to note, though, that the Marine Band's "Hail to the Chief" was broadcast live and direct. Semper Fi! [NYTimes]