2 5 1 Chord Progressions

IIm7-V7-Is

Why is this so important in jazz (and blues)?

We’ve discussed elswhere about how the harmony of music can imply a feeling of movement away from or towards a state of rest. This is what can make the music interesting (or boring), depending on the way you do it. Sometimes this is heard simply as tension and release, but often it can be formalised by thinking about three main areas: home, away, and returning. If you have done some basic theory training you will know that traditionally these main areas are associated with chords: Tonic (home) is chord I, Subdominant (away) is chord IV, and dominant (returning home) is chord V7. The V7 chord has a particularly strong pull back to the tonic chord due to the tritone interval between 3rd and 7th which has quite a lot of tension. The IV chord is still very common as a subdominant in blues (with a flattened seventh), but in modern jazz it is far more common to find a IIm7 chord functioning in the role of subdominant. Have a look on the jazz theory pages to find out more.

Important things about a IIm7-V7-I

The resolution from dominant to tonic is called a cadence and traditionally marks the end of a music phrase, like punctuation. There are different types of cadence, V7 - I is a called a perfect cadence. Apart from the obvious movement of the root notes downwards by a fifth, other notes of these chords have tendencies to move in a certain direction, and it can be very useful to exploit these voice leading tendencies when improvising your solos. Here are three very important voice leading movements, they are not of course compulsory, surprises can be good, but you should be aware of them and experiment with using them.

Chord	Note	Voice leading
Minor 7th	7th	Down a semitone to 3rd of dominant
Dominant 7th	3rd	Up a semitone to root of tonic
Dominant 7th	7th	Down a semitone to 3rd of tonic

Let’s look at this in a couple of different ways. First we’ll look at the chords played on a keyboard so you can see here how the voice leading works to make these chords progress smoothly from one to the next. In the first illustration the chords are shown as played in the right hand in root position, the whole chord moves up from Dm7 to G7, then down to C.

In this example, the G7 chord is revoiced so the notes move smoothly from one to the next, you can see how the C resolves to the B then up to the C, and how the F resolves down to the E.

Very often keyboard players and guitarists will try to voice chords so that there are smooth transitions from one note to the next.

The next two examples show how voice leading work with a simple arpeggio/scalic patterns which outline the chords

Here the C (7th of Dm7), falls nicely onto the B (3rd of G7) then up to the tonic C. (Note that although the C actually falls on the second half of beat four, anticiptations in jazz usually take the harmony of the chord on the beat which they anticipate).

In the next one the scale run down from B lands on the C.

The IIm7-V7-I chord progession is very common in jazz improvisation, many tunes consist entirely or almost entirely of IIm7-V7-Is, sometimes rapidly modulating through different keys (key centres) as in Giant Steps

It is totally up to the improviser when to choose to use voice leading like this. If you use it all the time then the lines will become very predictable, however it will often just happen unconsciously once your improvisation becomes fairly fluent, this is what the notes seem to "want" to do.

Juxtaposing the IIm7 and V7

Here is some good news...you don’t need to be totally precise about this. You can actually split this down into two areas rather than three and think of the IIm7-V7 almost as one chord. Certainly it sounds very neat when you get that voice leading of C to B on a Dm7 - G7, but it can work just as well to fit a IIm7 - V7 over just a V7.

Look at the second keyboard example above - the Dm7 chord is really no different to a G11, all it needs to make it a G11 is for there to be a G in the bass (G11 is often written as Dm7/G). "Ah, but a G11 is not a G7" I hear you say. The 9th is not an issue, it’s a note that can often be added to any 7th and adds just a very slight bit of colour, but the 11th (or 4th) is supposed to be a clash against the 3rd. Well, so it is, but when it resolves down to the 3rd, it has just functioned as a suspension, which is absolutely fine - tension and release.

Sometimes a tune will have two whole bars of a dominant 7 chord, e.g. the bridge of I Got Rhythm. Pianists can play two bars of B7, or they might play one bar of F#m7 and one bar of B7 (i.e. making it a IIm7 - V7 instead of just a V7). Or they might play 2 beats each of F#m7, B7 repeated:|F#m7 / B7 /|F#m7 / B7 / |. You, as a soloist, may not know in advance what they are going to do, but usually it doesn’t matter, whatever you play will either be spot on or add some tension to this area. As long as you make a good resolution when it comes round to the tonic, all will be well, especially if what you play has some melodic interest - something that in jazz cuts far more than just playing the right notes in my opinion.