Diminished seventh chord
Since stacking yet another minor third returns to the root note, the four inversions of a diminished seventh chord are symmetrical.
[3] Music theorists have struggled over the centuries to explain the meaning and function of diminished seventh chords.
[7] Jean-Philippe Rameau explained the diminished seventh chord as a dominant seventh chord whose supposed fundamental bass is borrowed from the sixth degree in minor, raised a semitone producing a stack of minor thirds.
He may have been talking of the augmented second in quarter-comma meantone, a tuning he favored, which is close to the just septimal minor third of 7:6.
In operas and other dramatic works, the chord was frequently used to heighten the sense of passion, anger, danger or mystery.
Bach sets the text so that the angry multitude's harsh reply on the word Barabbam is a diminished seventh chord: After Bach, diminished sevenths featured regularly in music to evoke the uncanny or a sense of impending danger.
A powerful diminished seventh chord heralds the resurrection of the murdered Commendatore in the final scene of Mozart's Don Giovanni (1787).
The dead man's statue comes to life and takes the Don down to Hell in one of the most chilling episodes in the entire operatic repertoire (Listen): In the early years of the 19th century, composers used the diminished seventh with increasing frequency.
In "Die Stadt", one of his darkest and most melancholy songs from Schwanengesang (1828), Franz Schubert conjures "the pianistic elaboration of a diminished seventh over an octave tremolo"[15] to convey the sinister rippling of the oars as the protagonist is rowed across a lake towards the town where his lost beloved once lived.
According to Edward T. Cone, "This famous arpeggiation seems to arise from nowhere to create an atmospheric prelude... and it dies away to nothing in a postlude.
The operas of Carl Maria von Weber, particularly Der Freischütz and Euryanthe, featured many passages using this chord.
According to his early biographer, Alexander Wheelock Thayer,[16] Ludwig van Beethoven spoke disparagingly of the 'accumulation of diminished seventh chords' in Euryanthe (1823).
Perhaps the clearest instance of the diminished seventh's power to evoke mystery and terror can be found in the passage linking the two final movements of Beethoven's Appassionata sonata, Op.
[17] The final movement of Hector Berlioz's Symphonie Fantastique reflects the influence of Weber [18] in its copious use of diminished seventh chords to evoke the spooky atmosphere of a Witch's Sabbath: "a sinister gathering of spectres, monsters and weird, infernal mocking creatures":[19] By the end of the 19th century, composers had used the diminished seventh so much that it became a cliché of musical expression and consequently lost much its power to shock and thrill.
In his Harmonielehre (1911),[20] Arnold Schoenberg wrote: Whenever one wanted to express pain, excitement, anger, or some other strong feeling – there we find, almost exclusively, the diminished seventh chord.
This uncommon, restless, undependable guest, here today, gone tomorrow, settled down, became a citizen, was retired a philistine.
Understanding what inversion a given diminished seventh chord is written in (and thus finding its root) depends on its enharmonic spelling.
Since the chord may be enharmonically written in four different ways without changing the sound, the above can be multiplied by four, yielding a total of forty-eight possible interpretations.
