(doto frame
  (. setSize 300 300)
  (. setDefaultCloseOperation JFrame/EXIT_ON_CLOSE)
  (. addKeyListener
     (proxy [KeyListener] []
       (keyPressed [e]
         (. channel noteOn (int (.getKeyChar e)) 64))
       (keyReleased [e]
         (. channel noteOff (int (.getKeyChar e))))
       (keyTyped [e])))
  (. setVisible true))