Extended Chords and Beyond
Beyond seventh chords, you have what we will call extended chords, ninths, elevenths and thirteenths. These are merely dominant seventh chords with additional degrees of the scale added. Due to the number of notes involved, on a chordal instrument, it becomes necessary to drop some of the notes out in order to play these.
Again, the dominant seventh chord consists of the root, third and fifth, and adds the flatted seventh from the scale. To build a ninth chord you add the "ninth" from the scale which is the second of the scale up an octave. In the key of C this would be a D note, so you would add this to your C dominant seventh chord, giving you C, E, G, Bb, and D. Remember from last month’s column that you can alter these chords.
For the eleventh chord you continue building on the ninth by adding the "eleventh", (the fourth up an octave), which would be an F note. This gives us C, E, G, Bb, D, and F. As was discussed last month, you can alter not only the fifth and ninth of this chord, but also sharp the eleventh, (C, E, G, Bb, D, and F#).
Lastly, the thirteenth would use the eleventh with an added "thirteenth", (the sixth up an octave). This would be C, E, G, Bb, D, F and A. Again, you can alter these as we saw before. In addition, major chords can have the sixth added, (C6 = C, E, G, A) and major seventh chords can also have the 9 added, (Cmaj9 = C, E, G, B, D). Minor sevenths can have a flatted fifth, (Cm7-5 = C, Eb, Gb, Bb), or a ninth added, (Cm9 = C, Eb, G, Bb, D). You can also have a minor chord with a major seventh, CmMaj7, (C, Eb, G, B). The third can be raised to a fourth in most chords to make a suspended fourth chord of that type.
So how does all this theory fit into improvising?. You can obviously use the arpeggios of these chords over the appropriate chord, but let’s go beyond that. For any dominant seventh, you can use any altered or extended arpeggio built on that dominant seventh chord. For C7 you can use the arpeggio for C9, C11, C13, C7#5#9. C7-5-9, C7#5-9, C7-5#9, C9#11 and so on. This allows you to either extend or alter the chord in your solo. You make the harmony even richer when you do this, and as mentioned last month, you increase the tension of these chords, making their resolution to the next chord even stronger. This will give your lines good, strong melodic force.
If you are playing these chords on a chordal instrument, you will need to drop out some of these notes at times. If you analyze the chords, you will note that the third has to be there to determine major or minor, and that the seventh has to be there to determine dominant or major seventh, These then are key guide tones for the improvisor. Roots and unaltered fifths can be dropped, especially since the bass player will often be covering these in his bass line. That means that altered tones and extensions are there too, which we will take up in next month’s column.
The main idea here is that you have a lot of paints in your box, so give them a try. No one thing will always work, so if something does not fit the current place you are trying to use it, try others. Remember that the only rule is that if it sounds good it is right, and if it does not it is wrong. Keep experimenting.