The ACO is making me read something I don't know how to read.
So now we need rules.
Rule 1: Reading I
Δ, M, and Maj all mean major.
-, m, and min all mean minor.
(That's very annoying.)
+ means augmented.
o means diminished.
(And rightly so.)
Enharmonic spellings are just fine.
(That's... totally necessary.)
Rule 2: Reading II
The default chord is the dominant seventh, which is a major triad with a minor 7th.
Thus, for a CM7, the M is raising the 7th, not the 3rd.
Contrariwise, for a Cm7, the m is lowering 3rd, not the 7th.
Rule 3: Reading III
Ninths are often added to:
dominant 7ths chords
major 7th chords
minor 7th chords, and
half diminished 7th chords.
Not fully diminished 7th chords.
Ninths are major unless otherwise specified.
All 9th chords imply the inclusion of a minor 7th.
Rule 4: Reading IV
A sharp or flat after the chord root modifies the root, not what's added to it.
B♭9 means (B♭)9 and not B(♭9).
Rule 5: Reading V
11ths are perfect unless otherwise specified, and imply the 9th and the 7th.
13ths are major unless otherwise specified, and imply the 11th, 9th, and 7th.
(11ths are usually omitted from major triad 13th chords because they clash with the 3rds.)
Alterations for 9ths, 11ths, and 13ths are set apart in parentheses.
If a chord does NOT imply all the thirds descending to the root, "add" is used.
C(add 9) = C-E-G-D, not C-E-G-B♭-D.
Rule 6: 6/9s
There are "6/9" chords.
They have major 6ths and major 9ths unless otherwise specified.
7ths are not implied.
C6/9 = C-E-G-A-D, with G being first on the chopping block.
Rule 7: Which One?
6 vs. 13
use 13 when the 7th is present.
use 6 when the 7th is not present.
sus vs. 11
use 11 when the 3rd is present.
use sus when the 3rd is not present.
♭5 vs. ♯11
use ♯11 when the 5th is present.
use either when the 5th is not present. Annoying!!
♯5 vs. ♭13
use ♭13 when the 5th is present.
use either when the 5th is not present.
Rule 8: Alts
Dominant 7th chords are often altered with ♯5, ♭5, ♯9, and/or♭9.
They can be altered simultaneously: C ±9/±5 = C E B♭ G♭ G♯ D♭ D♯.
Altered dominant 7th chords usually have a dominant function, resolving to tonic.
Otherwise, dominant 7ths typically remain unaltered.
Rule 9: Guide Tones
For dominant 7th chords, the 3rds and 7ths are called "guide tones."
Those two voices descend chromatically with descending fifth harmonic progressions.
Similarly, three voices descend chromatically when alternating between 7(13) chords and 7(♯9) chords in descending fifth harmonic progressions.
Rule 10: Voicings
There are "spread" or "open" voicings and "close" voicings.
For 13th chords, spread voicings have the root, 3rd, and 7th in the LH.
The 9th and 13th are in the RH.
For 13th chords, close voicings have the root in the LH.
The 3rd, 7th, 9th, and 11th are in the RH, usually with the 3rd or 7th as the lowest.
For sus chords, voice the 4th in place of the 3rd.
For 6 chords, voice the 6 in place of the 7th.
The 5th is always first on the chopping block.
Rule 11: Chord Progressions
Three common chord progressions are outlined below.
II-V-I can be:
IIm-V7-IΔ7 or
IIm7(♭5)-V7alt-Im6/9
I-VI-II-V is called a "turnaround."
III-VI-II-V is also a "turnaround." It can be:
iii-vi-ii-V or
III7-VI7-II7-V7
The 3rd and 7th exchange places for roots a tritone apart, so tritone substitutions can be made.
For example, III7-VI7-II-V7 can become III7-♭III7-II7-V7.
II7-V7-I can become II7-♭II7-I.
Rule 12: Blues
The basic blues progression is:
whole note I6/9 - whole note IV7 - whole note I7 - whole note I7alt
whole note IV7 - whole note IV7 - whole note I7 - whole note VI7
whole note ii7 - whole note V7alt - half note I7 - half note♭III7 - half note II7 - half note♭II7
Rule 13: Scales Part I
The blues scale is: 1-♭3-4-♭5-5-♭7.
The ♭3 and ♭5 are "blue notes."
The bebop or bebop dominant scale is: 1-2-3-4-5-6-♭7-7.
The bebop scale is most often used over the V7.
Beginning bebop improv - descending scales start on 1, 3, 5, or ♭7.
Rule 14: Scales Part II
There are more scales, too.
There are major scales, minor scales, and modes, but we know those.
Pentatonic: 1-2-3-5-6
Minor Pentatonic: 1-♭3-4-5-♭7
Locrian ♯2: 1-2-♭3-4-♭5-♭6-♭7
Lydian-Dominant: 1-2-3-♯4-5-6-♭7
Phrygian-Dorian: 1-♭2-♭3-4-5-6-♭7
Lydian-Augmented: 1-2-3-♯4-♯5-6-7
Mixolydian ♭6: 1-2-3-4-5-♭6-♭7
Bebop Major: 1-2-3-4-5-♯5-6-7
Whole Tone: 1-2-3-♯4-♯5-♭7
Octatonic/Diminished: 1-♭2-♭3-3-♯4-5-6-♭7 or 1-2-♭3-4-♯4-♯5-6-7
Diminished Whole Tone/Altered: 1-♭2-♭3-♭4-♭5-♭6-♭7
Rule 15: Chord-Scale Relationships
To find the right scale for a chord, write out the notes of the chord.
Fill in the scale, avoiding aug 2nds and consecutive half-steps.
