for hundreds of years, the augmented 6th sonority has interested composers and intrigued song analysts. right here, Dr Mark Ellis offers a sequence of musical examples illustrating the 'evolution' of the augmented 6th and the altering contexts during which it may be came upon. unusually, the sonority emerged from one of many final remnants of modal counterpoint to outlive into the tonal period: the Phrygian Cadence. within the Baroque interval, the 'terrible dissonance' used to be almost always linked to destructive textual imagery. Charpentier defined the augmented 6th as 'poignantly expressive'. J. S. Bach thought of an prevalence of the chord in a single of his forebear's motets 'remarkably bold'. in the course of Bach's composing lifetime, the augmented 6th developed from a comparatively infrequent chromaticism to a virtually usual point in the tonal spectrum; the chord displays specific chronological and stylistic strata in his song. Theorists started carefully to simply accept the chord, yet its inversional chances proved really contentious, as commentaries by way of writers as assorted as Muffat, Marpurg and Rousseau display. throughout the eighteenth century, the augmented 6th grew to become more and more major in instrumental repertoires - it used to be maybe Vivaldi who first liberated the chord from its adverse textual institutions. by means of the later eighteenth century, the chord started to functionality nearly as a 'signpost' to point very important structural obstacles inside sonata shape. The chord didn't, despite the fact that, completely lose its darker undertone: it indicates, for instance, the subject matter of revenge in Mozart's Don Giovanni. Romantic composers exposed far-reaching tonal ambiguities inherent within the augmented 6th. Chopin's Nocturnes frequently look beguilingly uncomplicated, however the floor tranquillity mask the composer's strikingly unique harmonic experiments. Wagner's much-analyzed 'Tristan Chord' resolves (according to a couple theorists) on an augmented 6th. In Tristan und Isolde, the chord's mercurial