A highly entertaining one, which I attended. Unfortunately for 4BarsRest's ghastly puns, though, we weren't packed together like sardines - or to put it another way, it was just a normal late night Prom. Some late nighters I've been to, there have been almost as many performers on stage as there have been members of the audience.
The Gruber which followed was equally entertaining also. One does feel though that Hardenberger probably earns enough money to invest in a stand for his mutes - last night they were plonked on a piano stool.