VolumeIV - Focus and Clarity: Music for Projects & Study (2 CD's) Centurie after Mozart’s birth, we still find hidden potencies in his remarkable music. The best-selling book The Mozart Effect® revealed that Mozart’s ability to sharpen our intelligence, to relax and soothe us, comes from actual physiological benefits stimulated by the unique properties of his melodies and harmonies. Author Don Campbell spent years sequencing Mozart’s most powerful compositions into this five volume series that delivers the Mozart effect in its purest form.