The piano accordion once ruled the roost in zydeco. It's still a rockin' instrument though!
Check out CDs by Corey Ledet, Lil' Nathan, Curley Taylor, and Lil' Brian & The Zydeco Travelers for some new school mastery. In the old school, you probably already know about Clifton Chenier! But there's also C.J. Chenier, Buckwheat Zydeco, Nathan Williams, Wilfred Chevis, Leon Sam, and Lynn August just to name a few.