But LHD 244 is unique in how it captures an art form evolving overa long period, and shows how it was transmitted from musician tomusician. This formal study of musical theory shows us how classicalmusic evolved out of liturgical chanting and towards the harmonicsophistication that Bach, Mozart and Beethoven would master

while avoidingaccidentally landing on the tritone, an interval so abrasive that it wasnamed diabolus in musica (‘the devil in music’).