Chord Of The Week 6/2/16 TWINKLEJAZZ4 - Jazz VI7 3rd & 7th chord frags

bigjon

TWINKLE JAZZ 4 

I'm building a solo jazz chord-melody arrangement of Twinkle Twinkle Little Star from the ground up, gradually introducing more complex extensions and substitutions as we go. The key is Cmajor, to keep the theory easy to follow. Video at the bottom of this post. 

Today we're looking at the 4th-to-last chord on the words "...how I...", which is A7, the VI chord, leading in to the Dm7 ii chord on the word "...wonder...". The melody note is F xxxx6x and the bass note is A 5xxxxx, in the video I play the chord as a A7#5 5x566x at 0:25. Initially we'll always ignore the bass note and the melody note. If we were playing in a group the bassist and melody instrument would be taking care of those in any case, so our job would just be to define the harmony above the bass note. We'll put them back in later to complete our solo jazz guitar arrangement.

 
Excursus on RE-HARMONISATION and SECONDARY DOMINANTS

But before we get to the voicing of the chord, a long excursus on how we arrived at a VI dominant chord in the first place. A conventional nursery-rhyme rendition of the tune would probably have a chord sequence of F C G C (IV I V I) for "how I wonder what you are": xx3211 x3x010 3x543x x3201x. But jazz strongly favours the forward momentum given when the bassline moves up in fourths (= down in fifths), as happens with the V I progression at the end of the line on the words "what you are." The C chord on the word "are" has a root note a fourth above the root note of the G chord on "what you". Jazz re-harmonisation extends this principle backwards from the end of the line, superimposing the ii chord Dm from the parent C major scale, so that the root note D under "wonder" is now followed by the note G a fourth above it. This is moving round the CYCLE OF 4THS of which you may have heard. Now for this week's chord we will extend the cycle of 4ths backwards another round, so we will crowbar the bass note A under the words "how I" and build the chord on top of that. Sticking with the C major scale, that gives us the vi chord Am, but Am to Dm sounds pretty feeble as a progression within the context of the line, so most of the time jazz replaces the vi chord with its dominant equivalent VI chord, here an A7 instead of an Am7. That has the effect of abandoning C major as the key centre and replacing it with a new key centre of D (minor in this case but we only find that out when we reach the D chord!) This is because a key centre is uniquely defined by a 7th chord, as there is only one 7th chord in the parent scale for each key. Going up the harmonised major scale, the ONLY dominant 7 chord is the V chord, a G7 in our usual key of C. So the harmonised C major scale I ii iii IV V vi vii I (root, 3rd & 7th only) is Cmaj7 Dm7 Em7 Fmaj7 G7 Am7 Bm7 Cmaj7 - Cmaj7 x3x45x, Dm7 x5x56x, Em7 x7x78x, Fmaj7 xx3x55, G7 xx5x67, Am7 xx7x88, Bm7 x x 9 x 10 10, and back to C x x 10 x 12 12. So the fact that our new chord A7 is a 7th chord means it MUST be functioning as the V dominant chord, and so the key has temporarily moved to D (minor). This re-harmonisation move is called a 'Secondary Dominant', where any chord which is not the I chord is approached from a dominant 7th chord built on the root note a 4th backwards from it. 

So, now we've decided to play some kind of VI dominant chord, how to arrange it onto the guitar? The key to getting a chord to sound jazzy is to ignore the 5th and focus instead on the 3rd and 7th. The 3rd note of the D harmonic minor scale D E F G A Bb C# (the temporary parent scale) up from A (the root note of the current chord) is note C# xxx6xx and the 7th note of the D harmonic minor scale up from A is note G xx5xxx. For solo jazz arrangements I recommend mostly putting the 3rd and 7th onto strings 3 & 4, to leave strings 1&2 clear for jazzy extensions and melody notes, and leaving strings 5 & 6 clear for bass notes. So our 3rd & 7th partial chord for VI7 chords is - 

VI7 - A7(no root): xx56xx or x x 11 12 x x 

 
As with last week's ii7 chord xx35xx or x x 10 10 x x I put down 2 versions of the 3rd & 7th on the 3rd & 4th strings: this week the first voicing that I'm using on the video has the 7th on the 4th string whereas the ii7 had the 7th on the 3rd string. If your chord progression is moving round the cycle of fifths (and in Jazz this happens a lot by design, see the excursus on re-harmonisation above!), where the root notes of this chord and the next chord are 5 notes of the scale apart, then by swapping which string out of the 3rd or 4th string takes the third of the chord, and which takes the seventh, from one chord to the next, you will create voicings that are right next to each other on the fretboard and will flow smoothly, here xx56xx into xx35xx. This is a (temporary) V chord followed by a (temporary) i chord, so forms the smoothest path from the dissonant Dominant 7th to the consonant Tonic chord. 

A reminder on lower case notation for the (temporary) i chord. In Nashville chord notation, a capital letter means that the third of the chord is major (four semitones above the root note), hence V7 and Imaj7 which we have seen in previous weeks, eg C major has a root note C x3xxxx and a major third 4 frets higher E x7xxxx. Lower case means that the third of the chord is minor (only three semitones above the root note) so in this case Dminor has a D root note x5xxxx and the third is F 3 frets higher at x8xxxx.
Now we'll add the bass note A 5xxxxx back in, and the melody note F (actually F's 'enharmonic equivalent' E# - same note, different name!) xxxx6x with is the #5 of the A chord as it is one semitone more than 5 notes away from A going up an A major scale. So the full chord with the melody note on top is - 

A7#5: 5x566x
as at 0:25 in this video of me playing a 30-second arrangement of Twinkle Twinkle Little Star

If you want to follow the series from the start, the first TWINKLEJAZZ CoTW, on the Cmajor I chord, is at
http://www.thefretboard.co.uk/discussion/64757/chord-of-the-week-2-1-16-twinklejazz1-jazz-imaj7-3rd-7th-chord-frags I'll also keep a running index to the whole series on that page.
And the previous CoTW in the series, on the Dm7 ii chord, is at
http://www.thefretboard.co.uk/discussion/67140/chord-of-the-week-30-1-16-twinklejazz3-jazz-ii7-3rd-7th-chord-frags

bigjon

Chord Of The Week Index updated with 131 discussions at

http://www.thefretboard.co.uk/discussion/598/chord-of-the-week-index

and if you want to work through the Twinkle Jazz series from the beginning the first in the series is at

http://www.thefretboard.co.uk/discussion/64757/chord-of-the-week-2-1-16-twinklejazz1-jazz-imaj7-3rd-7th-chord-frags

I'll edit the series with forward links as I go: the next CoTW Twinkle Jazz 5 on III7 3rd & 7th chord fragments is at

http://www.thefretboard.co.uk/discussion/68249/chord-of-the-week-13-2-16-twinklejazz5-jazz-iii7-3rd-7th-chord-frags