LA Phil Principal Trombone Nitzan Haroz demonstrates for a young musician in last Friday's Masterclass at London's Barbican Centre

Imagine, for a moment, that you're a young musician - say, a young trombonist or horn player - and you've gotten an invite to participate in a special music education symposium held at Europe's largest arts complex. What could be better than that?

Well, how about if two of the world's foremost authorities on the two instruments - the LA Phil's Principal Trombone Nitzan Haroz and Principal Horn Andrew Bain, respectively - led semi-private masterclasses, giving you individual attention and lessons on how to improve your playing?

I bet you'd think that was pretty great - priceless, even.