Hubbry Logo
search
logo

Diminished triad

logo
Community Hub0 Subscribers
Write something...
Be the first to start a discussion here.
Be the first to start a discussion here.
See all
Diminished triad

In music theory, a diminished triad is a triad consisting of two minor thirds above the root. It is a minor triad with a lowered (flattened) fifth. When using chord symbols, it may be indicated by the symbols "dim", "o", "m5", or "MI(5)". However, in most popular-music chord books, the symbol "dim" or "o" represents a diminished seventh chord (a four-tone chord), which in some modern jazz books and music theory books is represented by the "dim7" or "o7" symbols.

For example, the diminished triad built on B, written as Bo, has pitches B-D-F:

The chord can be represented by the integer notation {0, 3, 6}.

In the common practice period, the diminished triad is considered dissonant because of the diminished fifth (or tritone).

In major scales, a diminished triad occurs only on the seventh scale degree. For instance, in the key of C, this is a B diminished triad (B, D, F). Since the triad is built on the seventh scale degree, it is also called the leading-tone triad. This chord has a dominant function. Unlike the dominant triad or dominant seventh, the leading-tone triad functions as a prolongational chord rather than a structural chord since the strong root motion by fifth is absent.

On the other hand, in natural minor scales, the diminished triad occurs on the second scale degree; in the key of C minor, this is the D diminished triad (D, F, A). This triad is consequently called the supertonic diminished triad. Like the supertonic minor triad found in a major key, the supertonic diminished triad has a predominant function, almost always resolving to a dominant functioning chord.

If the music is in a minor key, diminished triads can also be found on the raised seventh note, viio. This is because the ascending melodic minor scale has a raised sixth and seventh degree. For example, the chord progression viio–i is common.

The leading-tone diminished triad and supertonic diminished triad are usually found in first inversion (viio6 and iio6, respectively) since the spelling of the chord forms a diminished fifth with the bass. This differs from the fully diminished seventh chord, which commonly occurs in root position. In both cases, the bass resolves up and the upper voices move downwards in contrary motion.

See all
User Avatar
No comments yet.