This is a Square 3 1/2" Disc	Clavisoft - Cue Time Software used with Compatable Clavinova digital pianos and Disklavier allows you to read the music and play as you normally would, so you ultimaletly control the tempo of the prerecorded instrumental backgrounds according to how fast or how slowly you play the keyboard. One Song -THE CHRISTMAS SONG (CHESTNUTS ROASTING ON AN OPEN FIRE)