The "dueling piano sing - a- long" format probably had its modern origins at Pat O'Brien's in New Orleans. The music of choice was Dixieland, 40's, and 50's music. The true roots surely go back further than that because as long as there has been at least one person to lead a song, there has almost always been someone to sing, or howl along. --howlatthemoon.com * Chopstix Piano Bar * Howl at The Moon