The standard guitar tuning (E A D G B e) contains a major third (four semitones) interval between the G and the B strings. Between all the other strings there is a fourth (five semitones).
The P4 tuning gets rid of this exception: a practical solution is to lower the bottom four strings to obtain E♭ A♭ D♭ G♭ B e and this is the tuning we'll use here (but you could equally well use E A D G C f).
Enjoy!
last revision: 20140218
With a guitar in standard tuning this is the diagram that represents the well known basic C major chord.
Diagram Notation
Let's see some other examples, always in standard tuning: G Major, C Major and F Major (played with the common "E", "A" and "D" shapes )
A couple of things to notice
regardless of the frets or strings where it is played! Wherever you put the "red dot", there you will have a Major chord. So where in standard tuning we would have to learn three shapes, with P4 we need only one.
We have four basic shapes to play this chord on four adjacent strings (these voicings are usually called "drop 2" voicings).
Notice how these shapes are identical to ones present on a guitar with standard tuning when played on the first four strings.
The difference is that now we can use these "drop 2" voicings all over the fretboard.
The little black dot on the first diagram shows where an unplayed root is. It's there for reference, and it's useful for those voicings that do not include the root.
As a little exercise we could use these shapes to play C7 in the four middle strings over the whole fretboard (notice the fret number that changes on the side)
In tablature notation | |||
Move it up "one string" and you have F7 over the whole fretboard
in tablature | |||
Notice how the last shape for 7+ (root on top) is identical to the first for m7 (root on the bottom).
The ♭2 interval in the third shape (5th on top) between the 7th and the Root has an interesting sound, but we can usually replace the 7th with a 6th without altering the function of the chord. The resulting shape would be
It is still true that these can be obtained from the half diminished shapes by flattening (a second time!) the 7th.
As exercise notice that in each case lowering the root (flat root?!?!) you obtain the four initial shapes of the Dominant 7 chord.
This is because a Diminished chord can be always thought as a Dominan7 to which a ♭9 (that is a ♭2) has been added and in which the root is not played.
Let's introduce a new "string set" (e.g. first, third, fourth and fifth string) and the voicings (usually called "drop 3" voicings) for the above chords
7 | ||||
m7 | ||||
7+ | ||||
m7♭5 | ||||
Dim | ||||
I'm not sure there's a common name for these voicings but following the same line of thought we can call them "drop 2 4".
These voicings can be easily obtained from the ones on four adjacent strings.
For example
can be obtained from
by dropping the 5th down one octave
7 | |||
m7 | |||
7+ | |||
m7♭5 | |||
Dim | |||
Here below is a review of the most common ones, showing how they can be played on the usual "string groups" we have seen so far.
The names of these four-note-groups are somewhat arbitrary (e.g. "9 no 5"), what really matters is the notes they contain (R 3 ♭7 9).
Some of them are very tricky to play because of their "close" intervals. For example the group of notes "C D E F" (called Tetrachord Major) contains two major and one minor second, and it will need to be "spred out" on distant strings to be playable.
For these cases I present the playable voicing over all possible string combinations (not only the usual three)
7♭5 | |||
7♯5 | |||
7+♭5 | |||
7+♯5 | |||
m7+♯5 | |||
Let's move to some different sounds. These are "closer groups" that span a 5th (regardless of the chosen name that might contain a 7th).
Maj add9 | |||
Maj add♭9 | |||||
Min add9 | |||
Min add9 | |||
Min add11 | |||
9 no5 | |||
7♭9 no5 | |||
7♯9 no5 | |||
7 sus4 | |||
7 sus♭9 | |||
Tetrachord Major | |||
Tetrachord Minor | |||
Tetrachord Harmonic | |||
Tetrachord Phrygian | |||
Tetrachord Diminished | |||
The questions then becomes: what kind of four-note-groups can I use to incorporate these sounds? Since we are only playing four notes, it means that we have to give up one note of the basic chord (Dominant 7: R 3 5 ♭7) for every extension we choose to add.
If we want to choose four notes from the five available (R 3 5 ♭7 9) we have five possible options
The second one (3 5 ♭7 9) is equivalent to a m7♭5 chord played from the third (that is: play a Bm7♭5 on top of the original G7).
The other possibilities correspond to
We can reduce the above list by considering those options that include both the 3rd and the 7th, since these are the notes that specify the harmonic "character" of the chord.
That gives us (sorted by number of extensions and root position):
Let's repeat the exercise for other chords and extensions, grouped in three columns as the "sounds families" that we might find in major and minor II-V-I cadences
Major II-V-I | ||
---|---|---|
II | V | I |
Minor ii-V-i | ||
ii | V | i |