Audio: major harmony (0:16)
|I ii iii IV V vi viio|
major harmony plays chord progressions in the key of C major. Bars 1-4 are played by a string ensemble and bars 5-8 by a clean electric guitar without reverb or any other added effect. The major harmony figure shows the score with the ensemble in staff notation and the guitar in tablature. The major harmony table lists the triads used in major harmony:
- Bars 1-2: the root moves up by fifth. All seven triads in the major scale are used.
- Bar 3: the root moves down by fifth in a vi-ii-V-I progression.
- Bar 4: repeats the last three chords in bar 3 with a different voicing.
- Bars 5-8: the progression, I-V-vi-iii-IV-I-IV-V, is known as the Pachelbel canon.
Major harmony is a pithy term to describe the process of writing functional harmony in a major key.
V-I is the bedrock chord progression in major harmony. The root moves down by a fifth. This is the commonest way to link any two chords in functional harmony, by moving the root down a fifth. ii-V, iii-vi and vi-ii all move by fifth down. viio-iii is movement by fifth down but is rare in practice because the diminished triad is usually treated as an incomplete dominant seventh. This is also the reason movement from IV is generally by step up, IV-V, or fifth up, IV-I, rather than fifth down, which would result in IV-viio.
A chord progression in major harmony invariably starts and ends with the tonic triad I. This raises the question of inertia: why bother leaving home when all you will do is return there? This is not that silly a question and trying to answer it leads to some interesting conclusions.
There are two ways to develop a harmony, by repetition and by variation. Development by repetition is a powerful and sometimes overlooked tool in harmony. It is perfectly feasible to design a progression containing only a few chords and to repeat it ad infinitum. The result might well be interesting. Development by variation is the solution when repetition becomes boring. A chord progression is one of two vehicles for varying a harmony, the other is changing the key by modulation.
Functional harmony has a simple approach to starting a chord progression: the tonic triad can progress to any chord.
I-any is viable voice leading. There is no preference as to what chord should follow I. You are free to move from the tonic to any degree of the scale. This means there are six chords to choose from, seven if you include repeating the tonic triad. This freedom to choose your jumping off point is a positive freedom and allows for a lot of flexibility in designing a chord progression. There are plenty of options to choose from next whenever you arrive at a I chord.
Varying the chords in a progression is the crux of a harmony. There are two broad approaches: a linear approach and a network approach.
The linear approach to chord progression is incremental: add one chord at a time to a progression. Take, for example, the single I chord. This can immediately be incremented to I-any, the any literally being any other chord. Choose ii to make the progression I-ii. Move the root of ii a fifth down to increase the progression to I-ii-V. This already provides a route home and the progression can be incremented to become I-ii-V-I. Now start the I-any process again.
This incremental approach works well in many cases. It may run out of steam in a long progression and that is where the network approach is helpful.
The networking approach treats a chord progression as an expansion of a single chord. Expanding a single chord into a series of chords expands harmony in the same way that a single path in a network can branch into multiple paths.
The network approach does not increment a progression it expands it. Take, for example, the progression I-ii-V-I. Target any one of the I-ii-V-I chords for expansion. Target the ii chord, for instance. Expand it to ii-iii-V-ii. The progression is now I-ii-iii-V-ii-V-I. Target another chord for expansion. Target iii for example. This time, instead of branching off, loop back to the I to make I-ii-iii-I-ii-iii-V-ii-V-I. Keep branching and looping as long as you like. The chord progression automatically expands in the linear direction
Combining the incremental approach with the network approach, with its branches and loops, is a simple, solid and comprehensive method for designing any functional chord progression.
The guitar part in major harmony is nearly, but not quite, valid functional harmony. It includes a parallel fifth between the tenor and soprano parts in the iii-IVb chord change between bars 6 and 7. The parallel fifth could be averted by changing the voicing, but it would result in a chord shape that would be extremely difficult to finger. Consequently, it is left in situ on the basis that its position in the upper parts masks its effect. Playing two part counterpoint on a solo guitar is difficult enough, playing four part functional harmony is nigh on impossible.