Stamping on banjo players who keeep jumping in (often over other quieter introductions) helps. Some people know who the offensive banjo player I have in mind is. A very good tenor player with absolutely no consideration for others and a range of guilty secrets.

A host who does not hold up the singing by holding court and telling shaggy dog stories to his immediate circle of friends also helps. Again, I suspect the guilty party knows who I mean (it isn't the Bard nor the Mixer)