lead bass and rhythm bass

I recently saw an Irish/celtic band that did this. One of the bass players played like she was playing an electric guitar, and the other just played the normal bass backing notes. I think it's an awesome idea especially if you have a really good bassist who can improvise well. you don't often here bass solos, but they sound great. So my advice is to have a sort of rhythm bassist playing the usual root notes, and one lead bassist who can play around the scale a bit.
Good Luck!
~Kori