The sounds of a digital keyboard are created by sampling acoustic instruments. Acoustic “real” pianos vary greatly in terms of tone among different models (i.e., grand vs upright), and the technique and expression of individual performers also impact the sound on many levels. As a consequence, higher quality samples that capture the nuances of a key-triggered hammer striking a piano string will create a more realistic sounding piano (i.e. how it sounds when a key is struck forcefully vs. a softer attack, or what a staccato or short strike sounds like vs. a full chord pressed down slowly). In addition to great samples, top quality digital pianos will be able to calibrate each player’s individual approach to the corresponding acoustic piano samples, so your percussive left hand comping action hits as hard through the speakers as you’re hitting the keys.