for use with Yamaha's SmartPianist app to access and control features of the instrument. Graded hammer The various graded or progressively weighted keys are: Graded Hammer Standard (GHS), formerly Hammer Effect (HE) or Action Effect (AE) Graded Hammer (GH or sometimes GHE), somewhat heavier than GHS. GH is also closer to the weight of real piano keys. Graded Hammer 3 (GH3), like GH, but GH3 incorporate a third sensor, thus making the key respond more like "grand piano" behaviour. GH3 allows the player to trigger the sound when depressed a second time, even when the note is still decaying, and the player has not completely released the key after the first push of the key. This makes some techniques such as a soft legato "trill" easier to execute. Graded Hammer 3X (GH3X) keyboard features an "escapement" mechanism that reproduces a slight clicking sensation near the bottom of the key travel. It has been designed in such a way that the click is discernible only on the lightest keystrokes, similar to the keyboard of a grand piano. Natural Wood (NW) is graded like the GH3 but also uses spruce wood to make the feeling even closer to that of the acoustic grand piano. Natural Wood X (NWX) provides the keys of the NW keyboard, yet also has escapement, giving an even more accurate feel. GrandTouch Keyboard has a longer key length. The longer distance between the edge of the key and its pivot point means that it requires less strength to push down. 88-key Linear Graded Hammers provide 88 levels of gradation (each key has its own weight). With NWX, it has the most accurate feel of any of the Clavinovas, although also found on some NW keyboards. Keyboard "feel" feature matrix for current models From Yamaha Clavinova microsite. From Yamaha Product Spec page. Tone feature matrix for three past generations and current models From Yamaha Clavinova microsite. From Clavinova Spec page. History From Clavinova's 35th anniversary website. Predecessors (YP and CV) YP (CVP Predecessor) 1983: YP-10, YP-20, YP-30, YP-40 – provided the "Stereo Symphonic effect" showing depth feeling to perform in concert halls and live houses, first pianos on the series. CV (CLP Predecessor) 1984: CV-100, CV-300 CVP and CGP models 1985: CVP-3, CVP-5, CVP-7 – First CVP series Clavinova 1987: CVP-6, CVP-8, CVP-10, CVP-100MA, CVP-100PE 1988: CVP-20 1989: CVP-30, CVP-50, CVP-70 1991: CVP-25*, CVP-35, CVP-45, CVP-55, CVP-65, CVP-75 1993: