The Virtual Paino works on the similar concept of Virtual keyboard. As you can transform virtually any surface into a musical keyboard. It uses “a red semiconductor laser module and holographic optical element” to project “a 25-key 2-octave keyboard onto the surface in front of it.” A CMOS camera detects which keys are pressed and accordingly notes are emitted from the speakers in the device. The keyboard has 3 other voices in addition to piano — organ, pipe organ and harpsichord.

The box-shaped device measures about 100 x 30 x 30 mm (4 x 1 x 1 in.) and weighs about 100 grams (3.5 oz.). It will be available in Japan from November 2006 for 15,000 Yen ($ 130).
Pinktentacle via Techeblog