St. Ignatius Music
Strange thing is: the root note itself is 1, not 0, in opposite to the normal way of counting something. Take it as it is – too late to change.
C major chord
Next step: we build the C major chord using these keys. We start with the root note C, add a third to get E and another third to get G, resulting in 1-3-5 if we describe it using intervals:
Audio (MIDI): C major (C):
The semitone intervals for this chord are root 4 3. For all triad chords the semitone intervals are either 3 or 4. But they are not used to name it – see above. So the scale note intervals are root – third – fifth. Fine if we take only the white keys. Problem is – we have notes between – the black keys. So there’s more than one third: a perfect third (the one we’ve used) and a minor third, the black key (Eb) below the E key.
C minor chord
If we use the minor third with the remaining keys we get the C minor chord, which can be written as 1-3b-5 (or 1-b3-5, b stands for down a semitone, b is called flat):
C minor (Cm):
C diminished chord
Another variation is to use the minor third together with a diminished fifth, resulting in a C diminished chord, 1-3b-5b:
Audio (MIDI): C diminished (Cdim):
Why is it called diminished fifth, not minor fifth? Both terms mean lowering an interval. If you flatten perfect intervals (unison, fourth, fifth and octave) by one semitone, the result isn’t called minor but diminished. Perfect intervals got their names because they sound perfect due to their frequency relation, an octave also can always be divided into a fourth and a fifth. They always invert to another perfect interval. When you invert a perfect fourth, for example C – F, it becomes a perfect fifth: F – C. On the other hand, a minor interval is any interval that inverts into a major interval and a major interval is any one that inverts into a minor interval. Finally, an augmented interval inverts into a diminished interval, and a diminished interval inverts into an augmented interval. If there was a minor fifth, let’s say C – Gb, it would convert into Gb – C, which is – an augmented fourth! So there’s no minor fifth.
By the way – the diminished fifth is also called a tritone and divides the octave symmetrically. It is enharmonic to the augmented fourth, but this is not the same if you see the intervals in the scale context. Lord have mercy.
Finally, we can also use an augmented fifth to create a triad, resulting in the C augmented chord, 1-3-5# (# for up a semitone, called sharp):
Audio (MIDI): C augmented (males):
Question: why not 1-3-5b? Look at the semitone intervals: the last interval from 3b to 5 is only two semitones, so it’s not a third!
Chords build upon the C major scale
If we want to build up a collection of chords for the C major scale we should include only those chords using notes from this scale. That means, the C minor chord as well as the diminished and augmented chord do not belong to this scale! If we build up triad chords using intervals of third we get the following:
If you count the intervals you can name all chords using the starting note as root note. For the scale intervals often Roman numbers are used, uppercase for major chords, lowercase for minor or diminished chords:
Question: why B diminished, not B minor? Count the intervals: both are minor thirds (or 3 semitones), the B minor has a minor and a major third.
A chord means playing three different notes together, so if you play E-G-C instead of C-E-G it’s still a C major chord. This is called a chord inversion, with the bass note not being the root. Triad chords can have three positions, root, first and second inversion. On a guitar often a note is played more than once: the E major chord everyone learns at first is usually played on all six strings with the root note E played on three strings.
C major 7th chord
Now with just triad chords it’s hard to play the Blues – there’s no tension, no release. Only happy (major), sad (minor) or somehow strange (diminished). To get more chords, we simply keep on adding another (major) third, which is the seventh of the root note, again using only notes from the scale, resulting in the C major 7th chord, 1-3-5-7:
Audio (MIDI): C major 7th (Cmaj7):
G dominant 7th chord
The above chord wasn’t really breathtaking. Now the same for the fifth note, resulting in the G dominant 7th chord, 1-3-5-7b:
Audio (MIDI): G dominant 7th (G7) C major (C):
Much better! The last interval is a minor third (3 semitones), resulting in a chord that wants to be resolved to – yes, our root major chord! Play G7 followed by C major (you’ve done this before a 1000 times…), you’ll hear it. Now G is the dominant (V) of C (), that’s why it’s also called G dominant 7th. The 7th chord build upon the fifth note always results in a dominant 7th.
G dominant 9th chord and more
Funny, let’s add another third to the dominant 7th. Wait, it must be a ninth, but the scale has only seven notes?!? Don’t care, just do it:
Audio (MIDI): G dominant 9th (G9):
That’s the G dominant 9th chord. Important for electric Blues like the Chicago and Texas style as well as for rock music. You can now add the next third, resulting in an 11th chord, and another third to give a 13th chord. That’s the end, because with the next third you end at the root note again.
Back to the seventh chords: for the triad chords build with thirds we found already 4 different variations. For the seventh chord there are even more variations possible, resulting in strange names like harmonic seventh, half-diminished seventh and minor major seventh. The names are all the result of the way they are generated, trying to use scale interval names. So let’s try to demystify some of them:
There are more seventh chords possible, and if you use just intonation () you also get chords like the harmonic seventh, which is similar to a dominant seventh chord with the seventh interval lowered by about a quarter tone.
C major and minor sixth and more chords
Want more? Sure – there are more chords around. Let’s take the sixth chords: easy to build, for the major sixth we just add the interval of a major sixth to our basic major chord to get the C major 6th chord (C-E-G-A):
Audio (MIDI): C major 6th (C6):
Needless to say that there’s also a minor sixth chord, basically a minor chord with a sixth note added. Note that the last interval has only 2 semitones, with this we stop using only thirds to build chords. Without this rule the number of possible chords increases again, if we use the basic definition of a chord – 3 different notes played together – we can play “chords” like C-C#-D-D#-E or even play all available notes together. Fortunately only a few of them are really useful. Most of them have been described already, so let’s take a look at the rest:
- Added chords: simply a note added to chord, like Cadd9 – C major plus a 9th (C-E-G-D)
- Slash chords: a chord played with an additional bass note, like C/E (E-C-E-G)
- Power chords: just root and perfect fifth (see intro), not a true chord, like C5 (C-G)
- Suspended chords: a triad chord in which the third is replaced (“suspended”) by either a perfect fourth (sus4) or major second (sus2), like Csus4 (C-F-G). If you build a sus4 on the fifth note of a sus2 they have the same notes, so all sus2 chords can be described as sus4 inversions – and vice versa.
That’s enough I think. Now let’s see how we can use them.
Special Chords, Chord Sequences and Substitutions
Although John Lee Hooker could play a Blues with only one chord, a song is usually build upon chord changes. A common example we all know is the dominant 7th followed by the tonic major chord, for example G7 – C. These chords are also useful when playing a solo: try to emphasize the chord notes, especially those which make a chord unique (like the 7th of a dominant 7th).
Simple songs are often build using tonic (root) major chord, subdominant major chord and dominant seventh chord, like C-F-G7. The subdominant is a harmonic alternative to the root with a repetitive character and is used in Blues for exactly this reason: first statement in tonic followed by a repetition in subdominant. Finally we have the dominant 7th, which leads back to the tonic. In Blues often all chords are played as dominant 7th chords, although only the subdominant and dominant chord notes belong to the major scale. This is allowed because the Blues is not based on the diatonic major scale. The problem is that you can’t describe Blues harmonies using classical music theory. One way is to think of combining minor and major pentatonic, the other is to use a mixolydian scale, which is basically a major scale with a flattened seventh. In Blues nearly everything that fits is allowed, so keep it in mind as loose recommendations.
Back to the chords. Even in Blues you can use more chords to vitalize your playing. Like building up a basic lick library for soloing you should have a solid set of chord changes and substitutions. Let’s take a look at some common chord sequences and substitutions beyond the tonic/dominant/subdominant thing. A basic rule for replacing a chord with another is that the root note should not alter and at that they share at least two notes. Example: for C major (C-E-G) this could be A minor (A-C-E). Also taking a chord and raising/lowering one note is possible. Don’t mix a chord substitution and chord progression: if you have the progression of a 12 bar Blues you can substitute a chord with another having the same function, keeping the backbone intact. You keep the 12 bars! Finally, don’t try to play it all together. Don’t create a wild mixture of 7th, 9th and 11th chords with augmented, suspended and diminished variations. Keep it simple, like the Blues.
Major/relative minor
One way to substitute a chord is to use it’s relative minor, the sixth degree. For example instead of C you play a Am. Or a C followed by a Am, it sounds like things turning bad. Another option, not that well fitting but also working is to use the third, Em in this example. While Am shares the root note and the third, the Em chord, although sharing two notes, doesn’t have the root note. That’s why Em is drifting further away from C as Am. Same applies to minor 7th chords.
Suspended 7th
Example: Old Love. Instead of the dominant 7th you can also use the tonic 7sus4 or 7sus2, like G7sus4 instead of D7 (leading to G). Note that the triad sus chords don’t have a third in opposite to the sus7 chords.
Diminished 7th
In Nobody Knows You When You’re Down the F#dim7 is used as a passing chord between F and C. Another example is Robert Johnsons Kind Hearted Woman Blues or Me And The Devil Blues. The special thing about the dim7 chord is that all intervals are the same – a minor third. This results in another specialty: there are only three dim7 chords possible, all other are enharmonic, sharing the same notes:
Audio (MIDI): F – F#dim7 -C:
Using scale notes it appears only on the seventh degree of the major scale. Because of having two diminished fifths it sounds very dissonant and can be used to substitute the dominant 7th, V7. The diminished 7th is also called demented chord by old Blues players. It is enharmonic to a 7b9 chord. In short: you can replace the V7 with the VIIdim7. You can also use it as a transitional chord after a dominant 7th if you use the dim 7 chord a semitone above – they use the same notes except the root note (see example 2)! Example 1: replace E7 (E-G#-B-D) with G#dim7 (G#-B-D-F), key: A Example 2: go from F7 (F-A-C-D#) to F#dim7 (F#-A-C-D#)
Augmented 7th
You can’t build an augmented chord on a major or minor diatonic scale because it is build using two major thirds. Similar to the dim chords there are only four Aug chords possible, again all others are enharmonic. Build up the augmented chords for each note of Caug (C-E-G#) and you’ll see that they all share the same notes, because it symmetrically divides the octave into three parts. Blues doesn’t use the diatonic scale, so it’s no surprise that augmented chords can be find here and not in folk or country music. If we play them as dominant 7th chords (aug7 or sometimes written 7+5 or 7#5 because it’s a 7th with an augmented fifth) we have another alternative for the dominant 7th chord. It has a jazzy, cool touch and fits good especially into minor Blues.
Audio (MIDI): C augmented 7th:
9th and 11th Chords
They have been described already and using only third intervals they are a save replacement for 7th chords giving a more dissonant sound. Often not all notes from these chords are used, the fifth is often removed from 9th and 11th chords. Especially on guitar most chords don’t have more than 4 different notes.
A special chord using an augmented 9th is the 7#9 (or 7+9 or simply 9) chord, made famous by Jimi Hendrix in his song Purple Haze, but played before by EC on I Feel Free or Outside Women Blues. This chord has a lot of Blues, because it’s five notes can be described by combining major and minor Blues pentatonic. It is also often used in Rock music.
Audio (MIDI): E7#9 (E7+9):
The Circle of Fifth
This is not a substitution but a chord progression: Songs like Nobody Knows You When You’re Down And Out don’t follow the 12 bar Blues progression, they use the circle of fifth. Take a look at the chords: C – E7 | A7 | Dm – A7 | Dm | F – F#dim7 | C – A7 | D7 | G7 E7 is the fifth of A7, A7 is the fifth of Dm and D7, D7 is the fifth of G7, and G7 is finally the fifth of C. You can use parts of this progression to move from one chord to another when playing a standard Blues progression.
Guitar Chords
So far we didn’t use any guitar. You can now use the to get the shapes for all different chords in all keys, but it’s easier to learn a few chord shapes which can be moved to the right position to give the chord you need. This is the great advantage over a piano or keyboard: once you know a chord shape you can easily shift it up and down the fretboard to get the chord in the key you wanted.
I use tablature to explain the chord positions, not the often used chord diagrams showing a vertical guitar fretboard. 0 means open string, x means don’t pick. Easy to read, easy to draw.
The Basic Open String Chords
These are the major chords we all started with:
C A G E D
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