In this paper the authors describe a new way of thinking about musical tones, specifically in the context of how features of a sound might be controlled by computer musicians, and how those features might be most appropriately mapped onto musical controllers. They believe that electronically controlled (and this includes computer-controlled) musical instruments need to be emancipated from the keyboard metaphor, especially in the domain of computer music, in which timbres can be created that go far beyond the physical constraints of traditional acoustic instruments.