We saw in the previous posting that, without even hearing the 1-chord that is sure to follow the 5 (V) 7th chord, most people, musicians or otherwise, would be able to sing or predict it beforehand. i.e. the chord for
the
You, In Happy Birthday to YOU.
and the
Wool, in Have you any WOOL?
This is not by accident. The V-dominant chord has some very powerful properties that explain why this is the case.
It is customary to use Roman Numerals to distinguish these chords.
So I IV & V define the Major chords in any Key.
Roman numerals in lower case, i.e. ii iii vi vii define other chords that are usually Minor and occasionally diminished.
So using the Key of C as an example
I would be C major written as C
IV would be F major written as F
V would be G major written as G
ii would be D minor written as Dm
iii would be E minor written as Em
vi would be A minor written as Am
vii would be B diminished written as B
o Consider the V dominant 7 chord ( for which as an example, in the key of C major is G7):
The first thing to note is what notes of the C major scale this chord uses.
G is the 5.
B is the 7.
D is the 2.
F is the 4.
Note: Here I am simply numbering the C major scale in the following way, using the everyday numbers that we are familiar with:
C D E F G A B
1 2 3 4 5 6 7
and pointing out which notes, these particular notes fall on and stating the relative number..
It just so happens that the 2, 4, and 7th degrees are the most highly unbalanced of them all. They
all want to resolve somewhere.
Compare the (Roman Numeral V7)
G7 moving to C major
You would expect adjacent notes on the keyboard to be closely related, but that is not so. However, the 5, G is very closely related to the 1, C.
To learn more about this take a look at the Circle of Fifths, where C and G are found next door to each other. You will also find out more about the Roman Numeral references above, and about how they fit in. To read about this now, click this link:
http://www.ar-group.org/smforum/index.php?topic=954.0 But back to our V7 chord, which is G7 in our example:-
The “B” in the G dominant 7 chord eagerly wants to resolve up to “C.”
The “D” in the G dominant 7 chord wants to resolve down to the same “C.”
And the “F” in the G dominant 7 chord longs to resolve down to the “E.”
It is hardly surprising that this chord has so much tension in it and no wonder when you resolve all 3 at the same time, you get one of the most popular chord progressions in music — and this is technically called the
perfect cadence.
And on a broader note, when you’re thinking about what inversions and voicings of chords to play next, look at how the notes of the previous chord are moving to the notes of the next chord. Are they smooth, strong resolutions? Could you pick another inversion of the next chord to create such a sound?
Music consists of tensions and resolutions, so as we play we are not just hitting the notes that we think are correct for that particular chord, but creating these wonderful tensions that need resolving. This produces that satisfying result, which is not only enjoyable, but as you explore the detail, is very fascinating.
In subsequent posts we explore how we build several other chord types.
Peter