Thanks Mark,
I must admit ... I'm not my most comfortable when doing the dueling routine, but it pays very well, and the energy of the room can be infectious. If there's any secret to it, it's not much different than any other performance ... "give 'em what they want." Simple, upbeat, fun songs with a hook they can sing along with. It's a 180 degree switch from Karaoke ... the idea is to unite the room as one choir, and not put a spotlight on any one singer ... including the piano players. There are certain "staples" that seem to always work (mostly all the songs Capt Russ hates), but the simple truth is: if you sell it, you can do most anything, as long as you pace the energy to suit the room.
There's lots of material on line if you do the research, but it comes down to humility, and heart. The audience is the orchestra ... I'm just one of the conductors.