‘Within one decade, roughly 1830–1840,’ says Harold Schonberg, ‘the entire harmonic vocabulary of music changed. It seemed to come from nowhere, but all of a sudden composers were using seventh, ninth, and even eleventh chords, altered chords and a chromatic as opposed to classical diatonic harmony…the romantics revelled in unusual tone combinations, sophisticated chords, and dissonances that were excruciating to the more conventional minds of the day.’
