One of my first memories of the Festival Hall is a concert 'conducted' by Gerard Hofnung himself.  The whole evening was hilarious.  I remember particularly musicians playing as they walked down through and across the auditorium from almost every door and the Valkyries, in full dress and winged helmets, riding in from the wings on children's scooters.  Gerard Hofnung was an original and his concert made me a lasting fan of his and the Festival Hall.