A Jazz Slant
Life is a lot like Jazz – it’s best when you improvise.
– George Gershwin
CHAPTER AIM: The Semitone and the harmonic texture of jazz
Gershwin Piano Concerto, 2nd movement
What is the harmonic texture of this music? In what language is it speaking?
It’s clearly a classical piece. It’s got classical name (‘piano concerto‘), and it’s being played by a classical orchestra here on a website dedicated to classical music.
And yet those clarinets entering (0.15) sound rather laid back, and when that trumpet comes in (0.21), it could be escaping from the window of New York bar. The harmonic language of this music speaks with a heavy jazz accent.
All that Jazz
Google a definition of Jazz, you get:
“…a type of music of black American origin which emerged at the beginning of the 20th century, characterized by improvisation, syncopation, and usually a regular or forceful rhythm.“
Improvisation in music is simply a musician making up what he plays as he goes. Bach, Mozart and Beethoven were all renowned for their brilliant improvisational skills. It’s actually a large part of how they composed.
Gershwin also was famous for his improvisational skills. At home, or our for the evening at a party: he loved to sit at the piano playing for hours (as Mozart and Beethoven had before). Making up music.
We can imagine fairly easily what improvisation means with regard to melody. Just picture a jazz saxophonist improvising, or a blues guitarist jamming away. But how about harmony?
Gershwin spoke on the subject towards the end of his life:
“I’ve always had a sort of instinctive feeling for tone combinations, and many chords that sound so modern in my orchestral compositions were set down without any particular attention to their theoretical structure.“
We can explain some of these ‘tone combinations’ by having a closer look at the piano keyboard.
Art Tatum plays Gershwin
When we listen to Jazz, we hear a harmonic language that seems to slip between the major tonalities. Jazz improvisation enjoys the closest pitch relationships you can find. Which for western music has always been the semitone.
If we look at a piano keyboard, an octave is divided into seven notes, which create the major scale. For C major, that means the seven white keys on the piano. Play the white keys, and you’ll get our familiar Do-re-mi of the C major scale.
But the octave is in actuality divided up by 12 black and white keys. These divisions are the smallest unit we use in western music, the ‘semitone’ (as we saw ). We term this semi-tone scale a chromatic scale.
His choice of keys are often surprising. Key changes are often leaps to new harmonic platforms, strange, remote and wonderful. But they are leaps: clear jumps to new plateaus. When Wagner exploits chromaticism- the contrast of the semitone – he does so to produce bright differences. To shift us into new harmonic space.
3.57- 5.59 Piano Introduction
With Gershwin, the harmonic space comes between the existing harmonic fabric; feeling around the edges, rather than planting flags in new territory, like Wagner’s music. This is music that is working from within. It’s as if jazz is cocking a snoot at the existing music order, rather than attempting to define a wholly new one.
That is why the semitone is so important in this harmonic fabric. An adjacent semitone is in very different tonal territory, and yet it’s as close in pitch as the previous note you can get (for a piano, at least). It’s the harmonic space a jazz performer is drawn to, particularly when improvising.
This harmonic exploration of musical space feel personal, even subversive.
A Jazz Concerto
Let’s put this into a practical context. We’re going to turn again to the piano solo (classical word: cadenza) we used last chapter, that comes 8 minutes into our movement. Listen out for the chords spread in the left (lower) hand of the piano:
7.55-9.34 Piano cadenza
- 0.02 Chord
- 0.06 Chord semi-tone lower
- 0.09 Chord semi-tone lower
- 0.12 Chord semi-tone higher
- 0.18 That run up the piano is studded with semitones
- 0.39 Again the chords in semitones…
- 0.41 …etc
It’s the same pattern – splayed chords, each a semi-tone apart. Those two notes remain the same in the right hand, but that shifting harmonic platform below gives those two notes a new harmonic slant with each chord change.
Once we become accustomed to this harmonics of semitones, we start to hear it everywhere.
Listen back to the very start of our piece, with the entry of the clarinets just after that short horn intro. The clarinets occupy the background sound, as against the trumpet in the foreground:
Clarinets entry (12 seconds)
- 0.00 The first three notes are all a semi-tone apart. Down then up.
- 0.06 More obvious again, four semitones going down…
- 0.09 Again, down then up, then down and up again
- 0.15 Again, three semitones going down…
- 0.20 Down then up, as in the start.
- 0.25 Again four semi-tones going down…
You get the idea.
Gershwin also uses semi-tones as semi-quavers (as opposed to grace notes), so they act as a spring-board to leap up. Here are an example of both grace note semitone and springboard semitones together, to help tell them apart:
These quick close semitones give the music a jazz harmonic texture. And they constantly pattern the music:
Piano entry (4 mins in)
- 0.01 Those three ‘grace note’ semitones
- 0.03 Again with one grace note. And again at 0.04.
- 0.05 That ‘springboard’ semitone lower. It comes in very quick.
- 0.09 Again the grace note.
- 0.10 That ‘springboard’ semitone
- 0.12 And another…
- 0.14 And another.
These repetitions constantly jab and punctuate the harmonic space, giving it the spring and bounce of jazz. It’s choc-a-block with semitones. They don’t exist to decorate, or add occasional harmonic spice, such as you’ll find say with Mozart.
They are everywhere, defining the entire musical landscape. It’s in the harmonic genes of the music.
Towards the Blues
Piano Solo (8mins in)
This is only the start of a fascinating subject.
We’ve talked so far about peering close into the harmonics of music, right up to the cracks. There we find the semitone. Only the harmonic language goes beyond this. Sometimes it actually drops between the cracks.
We’ve actually covered pretty much the entire movement, in separate chunks. That means, before we go, we can take our first overall view of the piece.
The Whole Lot
Gershwin Piano Concerto, 2nd movement
- 0.00 Our windy introduction. This section will provide filler for the rest of the movement.
- 3.57 The piano introduces a new lively section that builds…
- 6.10 A solo violin pipes up for an interlude.
- 6.28 Our windy introduction again.
- 7.58 A piano solo, playing with all our themes as discussed above
- 9.15 Our showtune section we’ve been looking at this chapter
- 12.31 Our windy section played now on piano. A coda.
The structure of the piece, the foundations underpinning the edifice, is now exposed.
Gershwin uses his ‘windy’ opening material three times, like the bread in a large club sandwich. At the front and end, and in the middle, as a bridge between the fast piano middle and the showtune finish. the structure binds three fairly separate sections into an entire movement. Hence:
- 00.00-03.56 WINDY Section
- 03.57-06.27 Piano Faster Section
- 06.28-09.14 WINDY Section (with piano solo)
- 09.15-12.30 Showtunes finale
- 12.31-13.28 WINDY Section coda.
Gershwin hasn’t used any particular traditional classical model to build this movement, and he was criticized by the more high-brow of his contemporary critics precisely for this, for a perceived lack of ‘structure’.
There’s plenty of structure here, just not a traditional classical model. Gershwin trusts his instincts, and they are spot on. Like all great composers, he doesn’t just follow a formula, but rather makes his own.
As he himself said, life’s better when you improvise.