In this lesson we'll look at block chords, used by jazz pianists like George Shearing, Bill Evans and many others. Block chords are effectively a way of harmonising a melody by having all the
notes move in parallel. There are a wide variety of ways to do this. We'll look here at some of the most common, all examples of what is known as four-way close harmony.
The first example alternates between C6 chords and dimished 7th chords:
Try playing up and down this series of chords. Notice how the upper line is a C major scale with a passing note of a G#. The reason for the G# is it allows the chords to
continue to alternate - if the scale was G then A, we would have to harmonise using two C6 chords, so the G# gives us another opportunity for a dimished 7th chord, and allows
the pattern to continue.
To see a piece that incorporate these chords, see On the block by David Bruce here on 8notes.com - there is a middle section to the piece
which allows you to improvise over a repeating left-hand pattern.
There are three alternative versions of the above, all alternating one chord with a diminished 7th chord. Firstly this one alternates minor 6th chords with the diminished:
The next one alternates minor 7th chords with the dimished 7th chords:
And finally, dominant 7th chords:
All four of these are very closely related, but you can see how they give a huge range of possibilies when improvising jazz piano.