I just got a residence as a duo ensemble at a small bar. It comprises of Rhythm Guitar/Lead Vocal and Bass Guitar/Backing Vocal. I've never done anything like this before, and I gotta say it's one of the best gigs I've played. Manly because I provide most of the rhythm AND I play all the melodies, fills and riffs. The rhythm guitarist just plays basic rhytrhm, but he is a very good vocalist, and that's his talent. So if you wanna "step out" and become the Lead Instrument, Duo ensemble is worth try. To my surprise, people really like it.