If the twelve unique pitches are the core of western music, then chords are the very next piece of the puzzle. Before you begin to learn about chords, it is very important and helpful to understand scales to the point where you don't have to ask yourself if Db is part of an Ab major scale. In western music, chords are built by "stacking thirds;" in other words, if you start on C, you can build a chord by going to the third note in C major, E. Do this one more time and you end up on G. So, now you have C, E, and G, which together make a C major triad (triad - three notes). You can use this tactic anywhere you please, and you will end up with a variety of results. This section will explain just what these results are and how you can use them to understand, play, and create music.
Triads are the most basic chords. Each contains three notes. If you try "stacking thirds" in a variety of places, you can derive four different types of triads. Note that stacking thirds is not specific to what type of third you should stack - there are minor thirds and major thirds and different combinations of these results in different triads.
A major triad can be constructed by starting on any note and then adding the note a major third above as well as the note a perfect fifth above. An easier way to understand major triads is to look at a major scale. For instance, if you wanted to know what notes were in an Eb major triad, take the first, third and fifth notes from the scale, in this case, Eb, G, and Bb. As with scales, all major triads are the same thing, only based off different notes.
From the perspective of stacking thirds, a major triad is created by stacking a major third (4 half steps) followed by a minor third (3 half steps). In a C major triad, C to E is a major third and E to G is a minor third.
Keep in mind that any chord you deal with can be played in many different ways. If you want to play a C major triad, you do not have play a C, then the E right above that, then the G right above that. You could switch the order and play a C, then G, then E. This still constitutes a major triad since it covers the three notes in a C major triad even though it is in a different order. Here are different variations of chords that would all be considered C major triads.
There is more information on the different voicings of chords in inversions.
As shown in the notation, the chord symbol for a major triad is a lone capital letter representing the root of the triad. A C major triad can be shown just using "C".
Minor triads are constructed with the minor third and the perfect fifth above the root note. If you examine a minor scale, the root, third and fifth all make up a minor triad. It doesn't matter which minor scale you use for comparison because the root, third, and fifth are the same in all three scales. A G natural minor scale is spelled: G, A, Bb, C, D, Eb, F, G; therefore, a G minor triad is spelled: G, Bb, D.
From the perspective of stacking thirds, a minor triad is built by stacking a minor third and then a major third above that. In a G minor triad, G to Bb is a minor third, and Bb to D is a major third.
As with major triads (or any chord, in general), you can play minor triads in a variety of ways. Check out the inversions section for more details.
The chord symbol for minor triads is similar to that of major triads except the capital letter is followed by a small "m". Therefore, a C minor triad would be shown as "Cm". You may also see chord symbols that use lower case letters to help emphasize minor: lower case is minor, upper case is major; however, following the letter with a small "m" is a more common version.
Diminished triads contain a minor third and a diminished fifth above the root note. Unless you look at an octatonic scale, there is no scale you can examine to find the notes in a diminished triad. The easiest way to remember how to find a diminished triad is to first build a minor triad, then lower the fifth (the top note of the triad) by one half step. For example, a G minor triad is spelled: G, Bb, D; therefore, a G diminished triad is spelled: G, Bb, Db - the D is lowered one half step.
If you stack thirds, diminished triads are built with two minor third intervals - G to Bb is a minor third, and Bb to Db is also a minor third.
As shown in the notation above, diminished triads are represented with a small ° symbol to the upper right of the chord letter much in the same manner that exponential numbers are shown in math. If you are using case sensitive letters, the letter would be lower case.
Augmented triads are the last category of triads. These triads contain a major third and an augmented fifth above the root note. If you want a scale to examine, augmented triads fit within a whole tone scale. However, the easiest way to find augmented triads is to take a major triad and raise the fifth by one half step. If you have a C major triad, spelled C, E, G, then a C augmented triad is spelled: C, E, G#.
Stacking thirds, augmented triads are constructed with two major third intervals. In a C augmented triad, C to E is a major third and E to G# is a major third.
Augmented triads are shown using a small "+" sign to the upper right of the capital letter.
Before you begin reading this section, you should be very familiar with all the triads since seventh chords are built on triads. Seventh chords are simply triads with another stacked third on top, which ends up being a seventh higher than the root note. Instead of a three note chord, seventh chords normally contain four notes (root, third, fifth, seventh). This section will cover the most commonly used seventh chords, although there are other combinations that create interesting sounds.
Major seventh chords are easy to remember because of the word "major;" you can build a major seventh chord using a major triad and adding a major seventh on top. In other words, if you wanted to build a C major seventh chord (commonly shown as Cmaj7, see graphic below), you would start with a C major triad (C, E, G) and add a major seventh (leading tone) - B. This gives you C, E, G, B.
If you have trouble figuring out what note is a major seventh above a certain note, look at the seventh note in the corresponding major scale. For example, if you wanted to know which note was a major seventh above A, look at an A major scale - A, B, C#, D, E, F#, G#, A. The seventh note is G#, which is a major seventh above A.
Dominant seventh chords are the other seventh chords based on major triads. A dominant seventh chord is built using a major triad and a minor seventh. Minor sevenths are just like major sevenths, only lowered by one half step; hence, if B is the major seventh of C, Bb is the minor seventh of C. For example, a G dominant seventh chord (commonly shown as G7, see graphic below) is spelled: G, B, D, F. If you wanted to change this to a G major seventh chord, you would raise the F to an F#.
Dominant seventh chords are named "dominant" because they are chords that generally lead the ear back to the tonic chord. Dominant chords usually start on the fifth note of the key you are in. For example, if you are in the key of C (major or minor), a G chord will act as a dominant chord since it leads back to C. If you are new to chords and functionality, you can listen to what I am describing by playing a C major triad (C, E, G) followed by a G dominant seventh chord (G, B, D, F). While playing this chord, you should be able to hear that the music naturally wants to go back to the C major chord; this is the natural resolution for the G dominant seventh chord. Keep in mind that when I say "natural" I am only referring to the traditions of western tonal music - there is nothing that mandates that a G dominant seventh chord resolves to a C major chord, it is simply the easiest and most convenient way to resolve the chord. If you intend to write music, you may or may not want to use traditional ways of resolving chords depending on the type of sound you want to create. Whatever you do, it is always a good idea to experiment and go beyond the basic foundations that are set up. There is much more information on these topics in the Functionality section.
Minor seventh chords are based off a minor triad and a minor seventh on top. For example, a C minor seventh chord (commonly shown as Cm7, see notation below) is spelled: C, Eb, G, Bb. If you already understand major seventh chords and dominant seventh chords, you should have no trouble finding any minor seventh chord of your choosing.
There are two seventh chords based of diminished triads, this is the first. A fully diminished seventh chord is based off a diminished triad with a diminished seventh. You can also think of this as three stacked minor thirds (three half steps each). You should already know major and minor sevenths; a diminished seventh is one half step below a minor seventh. If you are trying to find the different types of sevenths above C, a major seventh is B, a minor seventh is Bb, and a diminished seventh is Bbb. (B double-flat) A C fully diminished seventh chord is spelled: C, Eb, Gb, Bbb.
Now, you may ask, "Wait. Isn't Bbb just an A? Why can't I call it an A?" In all honesty, you probably should think of it as A. If you only concentrate on playing music, there is no reason to go into detail as to why it is Bbb and not A; however, make sure that if you are reading music and you see a note with a double sharp or flat, you still know what note to play.
If you are interested in theory or composition, you should examine the difference between Bbb and A. An explanation of this can be found in the Enharmonic Spelling section.
An interesting fact to note about fully diminished seventh chords is that every interval in the chord is a minor third: C to Eb, Eb to Gb, Gb to Bbb, and Bbb (A) to C. Because of this occurrence, there are only three unique fully diminished seventh chords. In other words, an Eb fully diminished seventh chord contains the same notes ( perhaps spelled differently) as a C fully diminished seventh chord.
The second of the diminished seventh chords is the half-diminished seventh chord, which is based off a diminished triad and a minor seventh. You can also think of this as a stacked minor 3rd, minor 3rd, and major 3rd. Fully diminished and half-diminished chords are very close to one another, there is only a half step difference. In the half-diminished seventh chord, the seventh is one half step higher (Same as the dominant 7th). Since you already know that a C fully diminished chord is spelled C, Eb, Gb, Bbb, then a C half diminished seventh is spelled C, Eb, Gb, Bb.
Half-diminished chords have a unique symbol. The symbol begins by using the same small º that is used in diminished triads and fully diminished seventh chords, but there is a diagonal slash through the º that distinguishes the half-diminished quality of the seventh chord. Although there is no such thing as a half-diminished triad, the number "7" still follows the half-diminished symbol.
The five categories above represent the common uses of seventh chords; however, not all the combinations of triads with sevenths are commonly used. For instance, there is no common name for a seventh chord based off a minor triad with a major seventh added. There is no rule that you cannot use this type of chord, it is just not used as commonly as the others are. You can also try out seventh chords using augmented triads (the more common one would include a major seventh). The point is that if you are looking to create your own unique sound in music, there are a world of possibilities beyond the standard rules that are set for western music. Many times it is useful to stay within the normal boundaries, but you are bound to discover new things about music if you explore how those boundaries can be surpassed.
If you already understand triads and seventh chords, you can continue the process by stacking another third above the seventh to create a ninth chord, or go another step and get an eleventh chord, or even one more step to create a thirteenth chord. If you look at blues music, these three other extensions are very important to creating different sounds on top of the same general progression of I, IV, V, I (see Functionality); however, in other styles, the ninth, eleventh, and thirteenth extensions are used mostly as embellishments on top of a more basic chord structure.
It becomes increasingly difficult to build any solid theory on these extensions since the possibilities for the chords you can build multiply each time. With a ninth chord, you could have a major or minor ninth on top of any the seventh chords. Then, what if all the notes of the chord were not present? With chords that contain many different notes (usually four or more), sometimes it is beneficial to leave certain parts of the chord out to help bring out the qualities of the notes that are still present. In seventh chords, the fifth is sometimes left out to allow the root, third, and seventh to speak more clearly. With ninth chords, the fifth could be left out, the seventh could be left out, or perhaps both the fifth and seventh are absent leaving you with the root, third, and ninth. Should you analyze and name each of these chords differently or should you group them all under one category?
If you ever glance at current music notation, you will most likely notice that everyone has a different way of notating chords, especially chords with the higher extensions (9th, 11th, 13th). The lack of a standard for notating chords makes most of this notation fairly meaningless and therefore not worth writing a whole section to explain. Most current music does not use chords in the traditional sense anyway - if the guitar plays an E power chord, the notation will probably show E5 as the chord symbol no matter what is going on in the other instruments. If you want to analyze musical examples that use the traditional chord setting, analyze some of the masters: Beethoven, Bach, Brahms, etc. If you are more interested in the composition of current rock music, take a few current songs and look at how the music does or does not make use of chords and how they are voiced differently from music of the classical period.
Suspension chords (commonly known as sus chords) are very similar to major or minor triads except that instead of a containing a third, they use a fourth instead (Root, fourth, fifth). In classical music, sus chords generally did not exist because the purpose of using the fourth in the chord was to add tension to the music before resolving the fourth down to the major or minor third. For example, play a C, F and G together (Csus4 chord), and then move the F down to an E. You will hear that the sus chord naturally wants to resolve to the major triad.
When sus chords resolve in this fashion (as they did most of the time in classical music), the sus chord does not actually exist. In the previous example, the F only served as an embellishment (a suspension, hence the name of the chord) for the C major triad; in other words, the E arrived a little later than the rest of the notes in the chord. In current music, many composers have begun to use sus chords as true chords in their own right; therefore the sus chord does not resolve to the major (or minor) triad, instead it moves somewhere else, perhaps to another sus chord. For a musical example of this technique, listen to the song, "When the Water Breaks" on LTE2 at 1:50. The piano plays various sus chords without resolving them in the traditional sense.
Up to this point, most of the chords have been shown in root position; that is, the root of the chord is also the lowest note of the chord. However, many chords are not played with the root note in the bass, resulting in an inversion of the chord. Inversions provide a way to change the sound of a particular chord, and they can also add variety to chord progressions.
Any triad or seventh chord with the third in the bass (in other words, the lowest sounding note) is a first inversion chord. Remember that the third of a chord refers to what would be the third note in the corresponding scale. In other words, if you wanted the find the third of a G major chord, you would look at a G major scale (G, A, B, C, D, E, F#, G) and see that the third note is B. Therefore, a G major triad with B as the lowest sounding note would be a G major triad in first inversion. There is nothing that dictates which notes go above the B; in this case, as long as the notes are G, B, or D, any voicing of the chord with B at the bottom would signify a G major triad in first inversion. Here are a few examples of first inversion triads and seventh chords:
As shown above, the chord symbol for a first inversion chord shows the chord name followed by the note in the bass. For a first inversion C major triad, the chord symbol would be shown as C/E. If it was a C dominant seventh chord, the chord would be shown as C7/E.
Instead of using the third in the bass, second inversion chords contain the fifth in the bass. Using the same logic as before, if you want to find the fifth of a chord, look for the fifth note in the corresponding scale. For example, to find the fifth of an F minor chord, find the fifth note of an F minor scale (F, G, Ab, Bb, C, Db, Eb, F), which is C. Therefore, an F minor chord in second inversion has a C in the bass. Note that when you use a minor scale to find a certain note in the scale you will most likely default to using natural minor as your scale. Here are some second inversion chords:
Chord symbols for second inversion chords work exactly like first inversion chords. The chord name is shown followed by the note that is in the bass. In other words, a second inversion F minor triad would be written as Fm/C. An F minor seventh chord in second inversion would be shown as Fm7/C.
Triads cannot extend past second inversion because there are only three different notes in the chord: one for root position, one for first inversion, and one for second inversion. However, seventh chords contain one extra note; therefore there is one more possible inversion. Any seventh chord with the seventh in the bass is a third inversion chord. There are many different variations of third inversion chords because there are many types of seventh chords. You may have a major, a minor, or a diminished seventh, in which case, the bass note will be slightly different. Here are some examples of third inversion chords. Note that in seventh chords, the fifth is optional depending on the type of sound you want to produce.
Again, chord symbols work in the same fashion as the other inversions. A C major seventh chord in third inversion would be written as Cmaj7/B. A C dominant seventh chord in third inversion is shown as C7/Bb.
When analyzing chords, be careful not to assume that all the chords are in root position. If you see a spot in the music that shows a C in the bass, but a higher instrument is playing an A, do not name the chord Cmaj6. If these are the only two notes shown, then most likely the chord is an A minor triad in first inversion (the fifth is optional, so it is acceptable that there is no E).