Lesson 2: Chords In Jazz

Intervals

Intervals are simply put, the distance between notes. Jazz makes use of all intervals and a knowledge of them will help your phrasing.

1 - 1 Unison - The note doesn't change.
1 - b2/b9 Minor Second - An interval of one semi-tone.
1 - 2 Major Second - An interval of a whole tone.
1 - b3/#9 Minor Third - An interval of a whole and semi-tone.
1 - 3 Major Third - An interval of two whole tones.
1 - 4 Perfect Fourth - An interval of two whole tones and one semi-tone.
1 - #4(11)/b5 Augmented Fourth/Diminished Fifth/Tritone - An interval of three whole tones.
1 - 5 Perfect Fifth - Three whole tones and a semi-tone.
1 -b6/b13 Minor Sixth - Four whole tones.
1 - 6 Major Sixth - Four whole tones and one semi-tone.
1 -b7 Minor Seventh - Five Whole tones.
1 - 7 Major Seventh - Five Whole tones and one semitone.
1 - 8 Octave - Same note an octave higher.

It is common for bebop players to start of a phrase with an interval of a fourth like in the head of "Ornithology" or "Scrapple From The Apple" by Charlie Parker. Beboppers also commonly end phrases with a major/minor sixth interval.

Chords

Major 7 - Maj7 or M7 or it can also be written as a triangle then a 7. Includes 1 3 5 7. Extensions are generally 9, #11, and 13. Commonly Major seven chords will be played as Maj6 or Maj6/9 chords,meaning instead of the seventh note of the scale they have the sixth and in the latter the ninth.
Minor 7 - Min7 or m7 or -7. Includes 1 b3 5 b7. Extensions include 9 11 and a natural 13.
Dominant 7 - Written simply as 7. (Ie C7) Includes 1 3 5 b7. Extensions include b9, 9, #9, 11, #11, b13, 13.
Half Diminished 7 - Min7 b5 or it can be written as a small circle with a line through it. Includes 1 b3 b5 b7. Extensions aren't generally used but would probably be limited to b9 and b13.
Diminished 7 - Dim7 or written as a little circle. Includes 1 b3 b5 bb7. Extensions aren't generally used but could include anything [depending on if the soloist/melody used the whole/half or half/whole diminished.]
Augmented 7/Dominant 7 #5 - Aug7 or +7 or 7 #5. Includes 1 3 #5 b7. Extensions are same as dominant.
Major 7 Augmented - Maj7 #5, Maj7 +5, M7 #5, M7 +5. Includes 1 3 #5 7. Extensions are generally not used, but could be similiar to dominant because of the altered 5.
Minor/Major 7 - Min/Maj 7, m/M7, or a - followed by a triangle 7. Extensions aren't generally used.
Suspended 4 - 7 sus. Includes 1 4 5 b7 3. Extension is usually b9.


Harmonizing The Major Scale:

When you derive chords from the major scale these are the chords you get:

I maj7 - ii min7 - iii mi7 - IV maj7 - V7 - vi mi7 - vii min7b5

If you add extensions you can make:

I maj6/9 - ii min 11 - iii 7 susb9 - IVmaj7#11 - V7 sus - vi min7b13 - vii min7b5

ii-V's and Movement in Fourths

The most common harmonic motion in jazz is movement of a fourth. The most typical way to do this is a ii-V-I. This happens in Autumn Leaves:

[Am7-D7-GM7-CM7-F#m7b5-B7b9-Em7-Em7]

It contains a Two-Five-One in Gmajor then it goes to the four, then there is a two-five-one in E minor. A minor two five is a ii-V that leads to a minor tonic. The minor chord is usually a half diminished and the dominant chord is usually a dominant flat 9.