I remember hoping that there was a filmed performance of John Williams conducting some of his movie scores, and so was happy to find out about the existence of this one.
He really is one of the very best, when it comes to film composers, and a two-hour set like this is bound to remind you why. Of course, it tells you what you already know in that way, and is exactly what you'd expect - but it's John Williams, and the music is (mostly) stellar, when it comes to how it's performed.
Watching this (or at least listening to it) is a no-brainer for anyone who likes film scores (I'd ordinarily say "for John Williams fans," but come on - if you like listening to music composed for movies, then you're guaranteed to like listening to Williams' diverse range of scores).