Definition of diminished seventh in English:

diminished seventh

noun

Music
  • 1The interval which is a semitone less than a minor seventh, e.g. from A to G flat (which in equal tuning sounds the same as a major sixth).

    • ‘‘There is a great deal more to writing for the musical theater than learning notation, the meaning of a diminished seventh, or banging away at a typewriter in some lonely room,’ he acknowledged.’
    • ‘Or the falling bassline of the organ-chorale symbolises the text of original sin through its falling over a ‘mournful diminished seventh’.’
    • ‘Tuning a five-string cello to C-G-D-A-D makes difficult-looking passages such as the diminished seventh in bars 3 and 16 remarkably easy.’
  • 2A chord formed by a note together with those above it at intervals of a minor third, a diminished fifth, and a diminished seventh. The resulting chord consists entirely of superimposed minor thirds, and is much used in modern music in modulating between keys.

    • ‘It is perfectly true that the work has the ambivalence that you have in the diminished seventh chord, and, therefore, when you're thinking of its tonality, it really could be almost any tonality within that hexachordal situation.’
    • ‘As with the chord of the diminished seventh in the past, these bring a new colour to the melody and the harmony.’
    • ‘It is as if this whining self-pity is the last straw for Edward, and with the fully diminished seventh chord in measures 64 and 65, Edward presents his Mother with a parting gift: ‘The curse of Hell from me shall ye bear.’’