Chord Of The Week 12/11/16 BEATLES CHORDS - A7/C#(noroot) from 'Blackbird' by the Beatles

bigjon

Only two different notes this week (= a 'diad') but an almost limitless depth of analysis available. The chord is the second chord of the second line, just after the word 'Take' in the line 'Take your wings and learn to fly', 0:23 in the video below. The chord is

A7/C#(noroot): x4x08x

The notes are C# x4xxxx and G xxxx8x plus the drone G xxx0xx which is sounded pretty much throughout the piece. These notes are an augmented 4th apart, the interval known as a tritone aka 'the devil's interval' popular in heavy metal riffs eg Enter Sandman by Metallica. So why do these two notes sound so sweet, even twee, here? It's a trick popularised by JS Bach where the lower note C# is followed by the root note D x5xxxx one fret up of the next chord x5x07x (Dadd4) and the higher note G is followed by the F# xxxx7x 3rd of the next D chord. This means that the C# and G are acting as the 3rd & 7th of a ghost A7 Dominant V chord which leads into the D chord in a V-I progression (this is called a Secondary Dominant since the A7 chord is outside the home key of G major - lots more on Secondary Dominants at http://www.thefretboard.co.uk/discussion/67731/chord-of-the-week-6-2-16-twinklejazz4-jazz-vi7-3rd-7th-chord-frags ). 

You can see Paul McCartney playing the chord at 0:23 in this video - 

bigjon

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