Hello music makers and welcome to this 7h episode of music theory in 5 minutes.
So far we have talked a lot about intervals scales and how to create chords, so today it is time to put that all together and talk about how to use these chords to build a chord progression.
To build a music, we'll build a chain of chords that we'll play in a certain order, with a certain rhythm, and this is this chain of chords that we call our chord progression; And there are certain rules, or tendencies rather, that you can follow to build them.
I actually don't really like to call them "rules" because following them is not really an obligation. Music theory hasn't been built as a set of rigid set of rules that you must follow. It's the music that has been made first and then we tried to find why certain things were working and those "rules" has been deduced from that.
It is part of the fun to try to break certain rules while making music. But following them is just a higher rate of success, so I guess it's better to know the rules before trying to break them. It's better to understand what you're doing to do it better.
Anyway so each chord of the scale has a number that we call degree, related to the number of the note in the scale.
From there you can put together a chain of chords using the chords in the scale you're using.
All the chords are from the same scale, the same tonality, it should work just fine.
So when you're using different chords from a tonality, some degrees in the scale will be sensed in a particular way, bringing different colours to the progression. Some will bring tension and some will bring resolution.
For instance, the chord V, which is called the dominant, will create a tension that will want to be resolved by going back to the chord I, the home chord.
This is because the first note and the fifth note of the scale have a special relationship, they are very consonant, so if the I is the home you search, V is like neighbour's home. When you see it you know you're almost there.
So the Vth degree brings a tension and the Ist degree brings a resolution
And this tensions and resolutions are something you want to play a lot with. Because writing music, I guess is a bit like writing a dialogue. Parts of your chains of chords or a melodic line would be sentences, and there would questions, answers and suppositions.
And some chord progressions that has been used a lot has become very recognizable and can be used like punctuation to build our sentences. These little chord progressions are called cadences.
The progression that goes V - I is called a authentic cadence. It's often prepared by a II, so the full authentic cadence would be II - V - I.
In C major, which is all the white keys of a keyboard, that makes Dm - G - C.
This is the most conclusive cadence, it acts like a full stop in a sentence. It's a good cadence to end a song for example, it's very conclusive, we finish with a big resolution.
If your sentence ends on the V (so often II - V), you prepare it like a perfect cadence but you stop on the V. Like an unfinished cadence, you stay hanging in the air.
This is called a half cadence, and it acts like a question mark or a comma. It creates a sentence that finishes on a little tension, and need to be answered.
You can also prepare an authentic cadence but instead of going the Ist degree, you go to a different degree. That is called a deceptive cadence - or an interrupted cadence.
The chord of the first degree is often replaced by the chord of the VIth degree.
So in C major that would be Dm G Am
This is not a conclusive cadence It's like we prepare the end of the sentence, but at the last moment we continue it for a bit longer.
The deceptive cadence is a great tool to break the expectations and add an element of surprise, to shift the mood of a sentence for example.
The last cadence we'll see here is when the progression goes IV - I.
It is called the plagal cadence. It is a conclusive cadence, that will sound like the end of a sentence, but it's as conclusive than the authentic V - I
It is used a lot in rock music for example
Now let's try to make a chord progression by taking advantage of all these cadences.
OK, let's by start by picking some chord at random to kick start our creativity.
So between 1 and 7, we have 4, 2, 7 and 3.
Cool that'd be our main chord progression (IV - II - VII - III), and I'll copy that 4 times to have 4 lines.
At the end of each line I'll insert the different cadences we saw.
On the first line, I'll squeeze the VII and the III in the same bar to have room to finish on a V, that's our half cadence.
On the second line I'll replace the III by a IV, and squeeze it in the same bar than the VII to have room to finish on a I. So we have a IV - I. That's our plagal cadence.