I was thrilled to talk with Dr. Diana Deutsch, a pioneer in the field of music perception and psychology (she literally wrote the book on music psychology). Diana has discovered a number of famous musical illusions. Prepare to have your mind blown by the octave illusion, the scale illusion, the tritone paradox, the mysterious melody, and the speech-to-song illusion "Sometimes Behave So Strangely," made popular by Radiolab. Diana also explains how composers can benefit from studying these perceptual illusions.