From what I can gather the owners site is based in Germany and the concert is from an Italian music performance, however I can play it without problems (I am in the UK).
Here is the actual You Tube channel here so you could try playing from there instead.
It is unusual for a video to start and then go blank if it is blocked, it normally just issues a warning that the video is unavailable (And the reason why), so check your web browser settings,(Including clearing the cache) or try a different browser.

Bill