http://www.wired.com/listening_post/200 ... al-is-sto/
Roland’s FR-7 V-Accordion, a second-generation digital accordion with 30 sounds, has a digital output that solves the problem. Using the company’s Physical Behavior Modeling technology, these accordions simulate the dynamic expression and other aspects of traditional accordions’ sound using algorithms rather than prerecorded samples. New sounds are possible thanks to a MIDI connection, so you could technically simulate an electric guitar or herd of elephants using only an accordion. An onboard digital amplifier uses power from a rechargeable Ni-MH battery to drive two neodymium woofers and two tweeters of the same type.