The illusions also show that people can differ strikingly in how they hear very simple musical patterns. For some illusions, disagreements tend to arise between righthanders and lefthanders, showing that they reflect differences in brain organization. For another illusion, perceptual variations depend on the geographical region in which the listener grew up, showing that the way we perceive music can be influenced by the language spoken around us. Using the principles that generate Deutsch's illusions, we can now produce music that sounds radically different from one listener to another, and even from one audience to another.

 The Compact Disc contains extensive spoken commentary, and comes with a 32-page full-color booklet which describes and illustrates the illusions in detail.