I'm the bassist in a trio that plays kind of psychedelic, progressive, jam based rock music. The other two guys plays drums and keyboard instrument (mainly Hammond organ) respectively. We have been talking about getting some new and fun instruments to play along with to broaden our sonic palette and expand our jam sections. The keys guy have a bunch of different synths, a mellotron, a Pianet and some other stuff. He also plays flute. The drummer has been bringing some percussion instruments to rehearsals. But what about me? What could I get into? Guitars are out, the principle of this band is "No six strings allowed". The synth and keys parts are covered. I already have a couple of FX pedals (delay, chorus and other) to play around with while playing bass. I have been thinking about Theremin, especially the Moog Theremini. I already have a cheap Theremin that I have used a bit, but it's hard to control volume and pitch on that in a live situation. Do you guys have any suggestions?