We continue exploring chord symbols by looking at two chord types we didn't cover last time: augmented triads and diminished triads.

The augmented triad has a root, a maj. 3rd, and an augmented 5th. Augmented (or aug.) means "larger," or raised by one half-step; in an aug. triad, the 5th is one half-step higher than a perfect 5th. Picture an aug. triad as a maj. triad with a raised 5th: the C aug. triad is C, E, and G-sharp.

The diminished triad has a root, min. 3rd, and diminished 5th. As you might guess, diminished (or dim.) means "smaller," or lowered one half-step; in a dim. triad, the 5th is one half-step lower than a perfect 5th. Picture a dim. triad as a min. triad with a lowered 5th: the C dim. triad is C, E-flat, and G-flat.

The symbol for an aug. triad is aug, or a plus sign: Caug and C+ both mean "C aug. triad." The dim. triad symbol is dim, or a circle; G dim and G with a circle after it both mean "G dim. triad."

You can add 7ths to these triads just as you can to major and minor triads. For aug. chords, the 7th can be either maj. or min. For example, a C+ triad (C, E, G-sharp) can have a B added (maj. 7th), or a B-flat (min. 7th). If it has a maj. 7th, the chord is like a CM7 with a raised 5th, which we call "C Maj 7 plus 5," or "CM7+5" (a triangle is often used in place of the "M"). If the 7th is minor, the chord is like a C dom7 with a raised 5th, called "C aug 7"; the symbol is "C+7."

Dim. triads can add a min. 7th or a dim. 7th; let's look at the dim. 7th first. A dim. 7th is a half-step lower than a min. 7th. For example, C to B-flat is a min. 7th. Lower the top tone even further (to B double-flat, which is usually just called A), and you get a dim. 7th. Add an A to a C dim. triad and you have a dim. 7 chord: e.g. C, E-flat, G-flat, and A (or C, E-flat, F-sharp, and A. The symbol is a circle and a 7 after the letter.

You can also add a min. 7th to a dim. triad, e.g. C, E-flat, G-flat, and B-flat. This chord has two names, each describing a different way of looking at it. It's a "min. 7 flat 5" chord (min. 7th chord with a dim. 5th), or it's a "half-diminished" chord (dim. 7th chord with a min. 7th rather than a dim. 7th). Either name is fine. The symbols are: min7 flat5 or -7flat5 (with a flat symbol in place of the word "flat"); or, or a circle with a slash through it.

If you see the word "sus" or "sus 4" (short for "suspended") in a chord symbol, it means play a 4th in place of the 3rd. Csus is C, F, and G. You can "sus" minor chords too: "C minor sus" is the same notes, C, F, and G. Why two names for the same chord? Because the 4th is seen as a 3rd that has been raised to produce tension, which releases ("resolves") when the 4th drops back down to the 3rd; the chord is called "suspended" because that resolution hasn't happened yet. If it's a maj. chord whose 3rd has been raised, it's called a "sus"; if it's a minor chord whose 3rd has been raised, it's called a "minor sus." Min. 7 and dom. 7 chords (but rarely Maj. 7) can be "sus" chords, too: both have a root, 4th, 5th, and min. 7th. Again, the chords are identical but the 4th in each will resolve to a different 3rd. Of course, you don't have to resolve sus chords if you don't want to , you can just play them for the unique sound that they have on their own.

If it's a "sus 2" chord, then the 2nd takes the place of the 3rd: "C sus 2" is C, D, and G. These chords are sometimes written as "C 2."

Last time, we began looking at chord extensions: 9th's, 11th's, and 13th's. In practical use, a 9th is a maj. 2nd above the root, an 11th is a 4th, and a 13th is a maj. 6th (just subtract 7 from an extension to get it's lower-than-8 "incarnation"). The 9th in a C chord is D; in an A chord, it's B; in a B-flat chord, it's C.

Next time, we'll explore how these extensions are used in chord symbols and chord voicings. Enjoy!


Copyright 2000 by Richard Middleton.
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