I finally checked this out and it is extremely impressive. It's a London Symphony Orchestra site that streams video of the orchestra performance (and audio of course). You may say that's nothing special but you can stream up to four different views at once, choosing among closeups from six different sections of the orchestra and changing any time throughout the performance. There's also an informative section about the orchestra itself and the presentation on the whole is smart and very slick.
Currently the only performance available to watch is Ravel's "Boléro". It was my first time to hear the piece but I enjoyed it - certainly well worth listening while exploring the site.