What is it about those rare and fleeting moments of musical beauty that fully captivate a listener’s attention? Does a composer calculate such junctures or are they happy accidents? How could a composer shape and guide the listener’s experience to create these events? Does detailed analysis of the notes tell us all we need to know to explain them? From Beethoven’s Sonata in E Major, Opus 109 to Leonard Cohen’s song, Hallelujah, as in many other works before and since, there are precise moments where a listener may experience a superb glimpse of ‘musical truth’. Understanding how and why they happen calls for an awareness of the psychoacoustic and social contexts for the musical experience and has unavoidable aesthetic implications for the way a composer thinks about music.