Page 117Seventh Chords with a Flattened Fifth
Another extended chord is formed by flattening the fifth of a dominant seventh – C7: C E G Bb becomes C E Gb Bb.
The 7b5 is close to a dom7 chord. Like the 7#5, it is used as a passing chord or to change key. There are several of
these in 'Moon River' and one in Santana's 'Smooth'
Chords of the Second Octave
To create these chords, the scale is extended over another octave:
CDE FGABCDE F GA B C
1 2 3 4 5 6 7 8 9 101112131415Any notes that the ear cannot distinguish as making any harmonic difference to the chord can be eliminated.
Therefore, 8 and 15 don't exist (because they duplicate the root note); neither does the 10 (which the ear hears as a
third), the 12 (which it hears as a fifth), or the 14 (which it hears as a seventh). That just leaves the 9, 11 and 13.
CDE FGABCDE F GABC
1 2 3 4 5 6 7 9 11 13These chords are difficult to voice on the guitar, and in the case of the full 13th, impossible – because it has seven
notes and the guitar has only six strings. Their harmonic complexity means they are sometimes unsuited to popular
music (unlike jazz, where they are heard all the time). They are much easier to play on a keyboard, where, unlike the
guitar, they can be voiced with the individual notes in sequence.
Major and Dominant Ninths
Ninth chords are formed by adding the ninth (that is, the secondof the scale an octave higher) to a seventh chord –
C7: C E G Bb becomes C E G Bb D; Cmaj7: C E G B becomes C E G B D. There is also Cadd9: C E G D, where the
seventh is missing.
These ninth chords are similar to their respective sevenths, if a little smoother. The dominant ninth is probably the
most significant of the three in popular music. It was used extensively in 1950s rock'n'roll, in 1960s R&B, soul and
funk, as well as in jazz. It is not quite as stark as the dominant seventh. The major ninth, compared to the major
seventh, is less lush sounding. The ninth in both cases has a ''diluting" effect. The add9 is tenser than either, with
more emphasis
Dominant ninths
continued