Hand held vocal coach from Roland

The pocket-sized VT-12 is a traveling vocal coach device. With a variety of built-in exercises and warm-ups, and analysis of your pitch while you sing. The illuminated pitch meter displays your pitch, and can even detect two singers simultaneously for two-part harmony.  It also has backing tracks and etudes from the Berklee Press bundled book
http://www.rolandus.com/products/details/1250/525

roland vocal trainer.