In Stock. 45 Day Lowest Price - 100% Satisfaction Guarantee. Yamaha makes it easy and fun to become a keyboard wizard with the introduction of the 61-key PSR273 Portable Keyboard featuring 61 piano-sized keys and a selection of some of the best voices available today, thanks in part to Yamaha's XG-Lite voice set. The PSR273 includes 480 realistic instrument voices, 32 notes of polyphony and Yamaha's Portable Grand technology which reproduces the most realistic piano sound available in portable keyboards today.