Defining dissonance would appear simple: “an interval that sounds discordant to the human ear”. And yet if one were to write a history of dissonance, it would be a fascinating journey through places and times, a panorama of all kinds of currents in the development of civilisation, a history of tonality and of its collapse, and finally a look at various ways of organising (that is, ordering) an infinite collection of sounds. This is not the time or the place to make such an attempt here. However, perhaps it is worth noting that there is no musical culture in which dissonance does not exist. What is its role, significance and status? These are important questions, perhaps even fundamental for the theory of music.
Dissonance is an integral part of one of the most elaborate chamber pieces in Wolfgang Amadeus Mozart’s oeuvre – String Quartet in C Major KV 465. It has become its customary subtitle. The listener is initiated into the main body of the Quartet through the fascinating sound of its opening Adagio. The series of dissonances that appear in the contrapuntally interwoven lines of individual instruments builds up an extraordinary tension that is begging to be resolved. Mozart exploited the potential of dissonance in a daring, even innovative manner; however, the power of dissonant chords was used to the full by his successors only several hundred years later. From the first bars of Béla Bartók’s String Quartet No. 5, it is the deliberate sharpness of the chords that determines the colour of the sound. Perfectly symmetrical in its construction, Quartet No. 5 was commissioned in 1934 by Elizabeth Sprague-Coolidge, an American pianist and patron of chamber music. When compared to Bartók’s austere work, Maurice Ravel’s String Quartet, composed more than three decades earlier (1902–03), sounds almost like an “incarnation of consonance”. It is hard to believe that the piece was deemed “barbaric” by the judges of a Paris composition competition. Apparently, the jury’s dissonance tolerance threshold was in a very different place than it is today. Everything is a matter of context – including the function and meaning of dissonance.