someone published a link somewhere (sorry, I continue to be useless at finding stuff on the fora) about that - Galway making a whole audience go ha-ha-ha in time to a beat...but that, basically, is the technique. Fantasien & Scherzi,
, has bits where you have to, er, vibrate, in time to a beat. Mine is ropey, obviously not enough experience in pantomime laughing.
I'm also trying to get a perfectly normal baroque piece to "warm up" in places - a very few, select, places - by means of a weeny bit of vibrato at the ends of very long notes. A weird experience for someone who really doesn't like the sound of the vibrato used in modern orchestras today...