The Yamaha Arius YDP-S55 features an improved Yamaha CFX concert grand piano sound engine and the touch of the revered Graded Hammer 3 (GH3) keyboard with synthetic ebony and ivory key tops. The YDP-S55 features a slim design, making it an ideal choice for those with space constraints, such as college students or those living in smaller apartments. Connecting to the Smart Pianist app for iOS adds a graphic user interface that makes selecting Voices or configuring settings even easier. Smart Pianist can even analyze songs stored in your music library and display a chord chart, allowing you to learn and play along with your favorite songs.

CFX Stereo Sampling faithfully reproduces the sound of Yamaha's flagship CFX Full Concert Grand. Graded Hammer 3 (GH3) with synthetic ebony and ivory key tops add a tactile surface to the keys, which absorbs finger moisture and prevents slipping. VRM (Virtual Resonance Modeling) Lite technology makes the sound more like that of a real acoustic piano by reproducing its sophisticated string resonance. Intelligent Acoustic Control (IAC) automatically adjusts the EQ of the built-in stereo speaker system to the player's setting, ensuring the richest tone at any volume level. Stereophonic Optimizer adjusts the spatial distribution of sound in the listener's headphones, creating the sensation that sound is coming directly from the piano, rather than from the headphones. Volume Limiter lowers the overall volume of the instrument so that you can protect your hearing with or without headphones. Three piano-style pedals offer authentic sustain, sostenuto and soft pedal performance. Half-damper pedal control allows for continuously increasing amounts of sustain as the pedal is depressed.

The Smart Pianist app not only gives you full control over your piano's major functions, but also analyzes your favorite songs right out of your music library using chord tracker technology. The 2-track song recorder allows players to practice or record one hand at a time.