Arnold Schoenberg
By Mark Berry
Reaktion Books, 224pp, £12/$19

Arnold Schoenberg was a composer much given to statements of sweeping portent which, even in print, seem to call for drum rolls and the clash of cymbals; and an example came in 1921 when he announced that he had “made a discovery through which the supremacy of German music will be secured for the next 100 years”.

His “discovery”, if that’s the word for it, was both equivocal and controversial: a method for writing music that challenged the foundations of tonality on which Western music had depended for four centuries. Tonality rooted a piece of music in a particular note: a home pitch that became the music’s key and gave it a structure which human ears identified as melody. But composers began stretching the rules of tonality from the mid-19th century onwards, starting with Liszt and then Wagner, whose slithery chromaticism in Tristan und Isolde was a landmark in the cause of liberation from home pitch.