Guitar Chords Explained

Understanding Chord Names And Symbols

This post is for beginners, though it may also serve as a refresher for more advanced players.

Any two notes played simultaneously constitutes a chord, though most chords on the guitar involve anywhere from three to six notes. And each chord has a name, based on the letter-name for its root (the lowest note, usually the bass note). In modern Western music, all chord names depend on the Diatonic Scale, meaning the Ionian Major Scale. This is the familiar “Do, Rey, Me, …” scale. It’s first note is called the “root”, is given the number 1, and the other notes, 2 to 8 in one octave, are counted in ascending order.

All chord names are based on this scale, no matter the Key in which the chord appears. And each note in the chord is given a number from 1 to 13 (i.e., first, second, third, … , thirteenth). A fundamental chord is the triad made up of the root, 3rd, and 5th. To make a 4-note chord out of a triad simply add the octave of the root. But you can also add other notes instead, up to three on other strings. You can also omit either the 3rd or the 5th to get up to four higher notes in the chord, but normally you must retain the root and at least the 3rd or the 5th for the chord to be recognizable.

Special Note: The sharp sign # means raise by a half-step. The flat sign 𝄬 means lower by a half-step.

In the Diatonic Scale whose root is that of a chord, and there are no changes to any of the notes in the scale, then that chord is called a “Major” chord. Example: If the note C is the root, then the Major triad has C, E, and G, as the 1st, 3rd, and 5th, respectively. Any Major chord is labeled by the letter-name of its root. So, C-Major is denoted by the letter C all by itself. If you see any lone capital letter from A to G as a chord name, or the in-between chords (A#, D#, G#, etc.) then assume it is Major But if the 3rd is flatted by a half-step, then that note is called a “Minor 3rd”, and the chord is called a “Minor” chord. In other words, all Minor chords have flatted thirds.

Minor chords are designated by attaching the lower-case letter m to the right of the letter-name of the chord. Examples: Am, Bm, Cm, etc., pronounced “A-Minor, B-Minor, C-Minor,” and so on. Yet, if the 3rd is sharped by a half-step, then the chord is called a “suspended” chord, and is designated by adding the suffix “sus” or “sus4” to the letter-name. Examples: Asus, Bsus4, etc. The abbreviation “sus” means the 3rd is sharped a half-step, while “sus4” means that the 3rd is replaced by the 4th, though this amounts to the same thing within the Diatonic Scale. In the first case, suspended means raise a half-step, while in the second case it means the 3rd is omitted (that is, suspended), and the next higher note in the scale is used instead (which is the 4th).

Another suspended chord, however, is the “sus2”, which means the 3rd is replaced by the 2nd, which makes sense when the term “suspended” is taken to mean “taken out” or “omitted”, so that the next lower note is used instead of the 3rd. Examples: Dm is made of D, F, and A. Dsus is made of D, F#, and A. While Dsus2 is made of D, E, and A.

An “augmented” chord is where the 5th is sharped by a half-step, while a “diminished” chord is where the 5th is flatted by a half-step. An augmented chord does not appear naturally in the Diatonic scale, so it is considered an “altered” chord in all cases, but a diminished chord does, and is therefore considered a “natural” chord type. Examples: Aaug = A+5 = A+ is made of A, C# and E#. Adim5 = A-5 is made of A, C#, and E-flat. All augmented chords, whether Major or Minor, and the Major-Diminished, are considered altered chords, while the Minor-Diminished is viewed as a naturally occurring chord in the Diatonic Scale.

Other chord types are obtained by adding more notes from the scale to the said triad (root, 3rd, and 5th), or at the very least to the root and 3rd or the root and 5th. The 2nd is not generally used in such chords (though there are exceptions), nor the 8th, 10th, or 12th, because the 9th, often used, is actually the octave of the 2nd, while the 8th is the octave of the root, the 10th is the octave of the 3rd, and the 12th is the octave of the 5th, so the 2nd, 8th, 10th, and 12th are not typically used in naming chords.

In the Diatonic Scale, a chord is built-up from the root by including every other note in the scale, ascending. So, the root, 3rd, and 5th make up the fundamental triad, but next adding the 7th, 9th, 11th, and 13th will create larger fundamental chords. Example: C7 has the root, 3rd, 5th, and 7th. However, as you count up from the 7th, the rule is to include the lower notes down to the 7th as you go. Examples: C9 has the root, 3rd, 5th, 7th, and 9th. C11 has the root, 3rd, 5th, 7th, 9th, and 11th. And C13 has the root, 3rd, 5th, 7th, 9th, 11th, and 13th, technically speaking, although a 13th chord has more than six notes, so the 11th is usually omitted to make room for the 13th note (with the exceptions that full-fledged 13th chords can be played on 7-string and 8-string guitars).

To escape this rule, you can use the “add” specifier to add any note to any given chord. Example: A(add9) attaches the 9th without the 7th to the A-Major triad.

Of additional concern with 7th chords, however, is that there are two kinds of 7th notes. In the Diatonic Scale, the 7th is naturally a half-step lower than the 8th note, meaning it is a half-step below the octave of the root. That kind of 7th is called a Major-7th, denoted as “maj7” or “Δ7” in chord names, but is also called a “perfect 7th in chord theory. For this reason, in chord theory, but not in chord names, a plain 7 is used for a perfect 7th, while in chord names it must be indicated by the “maj” abbreviation or the Δ symbol (the capital Greek letter Delta). On the other hand, flatting a perfect 7th by a half-step gives what is called the “Dominant-7th “, which was a label given it in medieval times because of the way it sounds compared to the Major-7th. In chord theory it is designated by a flat sign attached to the number seven, 𝄬 7, while in chord names the plain 7 is used. So, if you see a plain 7 next to a chord’s letter-name, assume it is the Dominant-7th, while the Major-7th must be designed as “maj7” or “Δ7”. If this seems contrary, remember that it is one of the differences between chord theory and chord names.

Another symbol is Ø, called the “minuscule” or “slashed O”, which is used for the Minor-Diminished chord that naturally occurs in the Diatonic Scale. Also, the + and – signs are used generally to denote sharping or flatting by a half-step, respectively, instead of the usual sharp # and flat 𝄬 signs, as long as the two sets of two symbols are used in some consistent manner. For instance, +5 and #5 are interchangeable for denoting the aug 5th, but you would not see both pairs of symbols used this way in the same context.

Now we return to altered chords, also called “alt” chords. Any chord can be altered by sharping or flatting any of its notes, and/or by omitting one or more of its usual notes. Example: A7+9 is an A 7th chord with a sharped 9th. The “7alt” is a special but common specifier for an altered chord in Jazz music, and for which the rule is that a Major chord with the 5th omitted is used along with the Dominant-7th, and which includes an altered 9th, 11th, and/or 13th. Example: A7alt involving a +9 and a -11, though the +9 and -11 are not specified. The trouble with this designation, however, is that the alterations are not given, and are therefore left up to the player, which can cause dissonance if two or more players of chords are allowed to choose their own alterations when playing together. In that case, it's best to be specific. Example: A7+9-11.

The most-used chords any guitarist needs, for beginner to advanced players, are given in my free lesson-book online at https://hkurtrichter5.wixsite.com/guitar-lessons .
Click “Blog” at the upper left onsite, and check out Lessons 2, 10, and 11.
 
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