Yamaha has created a digital piano that sounds like an acoustic one with the same key, level and hammer mechanisms. They say that their Avant Grand, with 4 embedded speakers, even feels like a real piano. At about 4 1/2 feet, half the size of an ordinary Grand, it has upgradeable software and the company’s TRS (Tactile Response System) that reproduces reverb to make it sound and feel more like the real thing. The Avant Grand will set you back about $20,000, about one hundred grand cheaper that Yamaha’s CFIIIS concert grand. Look for the debut in July.