"PLAYABILITY: the ease with which an instrument can be played, relative to the player's comfort and the effort required to produce the desired result. " http://www.taylorguitars.com/guitars/referenc...
"What do you mean by playability?
A mouthpiece that has good playability means that you don't have to fight it to play whatever you want on the saxophone or clarinet. Low notes as well as high notes come out effortlessly and in tune without adjustments from the player. Articulation and tone quality are no problem. If you are playing with the proper air support and embouchure tension, a good mouthpiece will play the entire range of the instrument without the player having to adjust; that's playability." http://www.jodyjazz.com/faq.html
"Jedes Instrument wird vor der Auslieferung in unserer Werkstatt auf Verarbeitung und Spielbarkeit geprüft. " http://www.musik-schmidt.de/osc-schmidt/
The Oxford Dict. of Eng. 2003 lists "playability" as a noun derived from "play".
sich spielen (5 a, 6 a, d) lassend:
diese Etüde, Rolle ist kaum s."
Quelle: DUDEN - Deutsches Universalwörterbuch
I disagree with "play ability" as "-ability" is a suffix similar to "-bar"; a "play ability" (if it existed) would be an ability to play, meaning that the game or instrument was able to play. "Playability" comes from "playable" = "spielbar"; "-ity" = "-keit". I also disagree with the idea that the word originated in the 1990s:
"But indeed this is a very different matter, and one bound up with the subject
of play, and the precise amount of playfulness, or playability, to be looked for in the world. " (Virginibus Puerisque and Other Papers, Robert Louis Stevenson, 1881)