Modifiers:


When reading a chord symbol, a chord is either standardized or modified.  Modified chords are composed of a root (standardized) chord and a modifier, which is enclosed in parentheses.  Modifiers serve three purposes: addition, subtraction, and alteration. 


Addition:


To add a voice to a standardized chord, simply place the number of the scale step in parentheses.


Example:  Cm7(4)  =  1  b3  4  5  b7


Because a fourth scale step is not present in Cm7, it is understood that (4) indicates an addition to the root chord. 


Some scenarios, however, require using the term “ADD” to avoid confusion.  The perfect example is C(ADD9).


Example:  C(ADD9)  =  1  3  5  9


If  one was to mistakenly name this chord C(9) in an attempt to describe a major chord with an added ninth scale step, this would be confused with a C9 chord.  The solution is to use the “ADD” notation.


When naming a chord containing scale steps of the same number (for example b5 and 5 within the same chord) “ADD” must also be used.


Example:  C6(ADDb5)  =  1  3  b5  5  6


Because the root chord (C6) contains a fifth scale step, notation of this chord without the “ADD” nomenclature would be interpreted as a C6 chord whose fifth step is lowered one half step (instead of an addition to the root chord).  To avoid this situation, it is preferable to manage the notation of this chord in the following manner.


Example:  C6(#4)  =  1  3  #4  5  6


Subtraction:


Subtraction, or omission of voices from the root chord, is accomplished by placing the notation “no” or “omit” in parentheses.


Example:  C9(no5)  =  1  3  b7  9


Alteration:


Alterations are accomplished by placing the variations on the root chord in parentheses.


Example:  Cm6(#5)  =  1  b3  #5  6


Because the root chord (Cm6) contains a fifth scale step, the notation is interpreted as an alteration of this step.


Some alterations are unique as they provide both omission and addition.  Suspended alterations are excellent examples of this.


Example:  C7(sus4)  =  1  4  5  b7


Because suspended chords possess no minor or major third, “sus” notation results in the omission of the root chord’s (C7) third scale step and the addition of the fourth.


Slash chords:


Another modification to standardized chords is the “slash” chord symbol.  This symbol is used to indicate a chord which contains an altered bass note.


Example:  C/G  =  5  1  3  5



CHORD BUILDING


Too many voices, too few strings:


When building chords, the limitations of the guitar will become apparent.  Chords such as Cm13 contain seven voices, while the guitar, however, has six strings.  Even chords containing six voices are nearly impossible to translate to guitar (with all voices represented) due to the tuning of the guitar and the limitations of finger span.  The solution is to represent the most important voices of the chord, adding additional voices after this has been accomplished.  The following is a list of necessary voices that must be represented in any chord that is built:


3 or b3


7 or b7


top voice (13 in a C13 chord, 9 in a C9 chord etc.)


Other than these voices, all other voices are expendable.  Additional voices are fillers that add depth, but can be discarded to facilitate easier fingering of the chords.  While it is not absolutely necessary, most players choose to represent the one or “root” when building their chords.  Usually there is adequate room to represent the root; the addition of the root helps to establish the tonal center of the chord. 


Under certain circumstances, the fifth scale step (and other voices) must be represented.  The following is a list of these exceptions:


#5 or b5 (diminished or augmented chords)


5, 2 or 4 (suspended chords)


Chord numbering system:


The numbers that compose the chord formulas and their modifiers correspond to the steps of the major scale.  Numbers greater than seven indicate scale steps one octave higher than the other voices.


Example:  (C major scale used for demonstration, any major scale is applicable) 


C    D    E    F    G    A    B    C    D    E    F    G    A    B


1     2     3    4     5    6     7     8    9    10   11  12   13   14


“Sharped” or “flatted” numbers correspond to the remaining chromatic scale steps.


Example:  (C chromatic scale used for demonstration, any chromatic scale is applicable)   


C        #C/bD        D        #D/bE        E        F        #F/bG        G       #G/bA      A      #A/bB    B


1         #1/b2         2         #2/b3          3        4         #4/b5         5       #5/b6        6       #6/b7     7


8         #8/b9         9         #9/b10       10      11       #11/b12     12       #12/b13   13   #13/b14  14         



IMPORTANT TIPS


Same name, many symbols:


Different manuscripts, fake books, and even composers, use different chord symbols.  While it is preferable to use different symbols for different chord families (m7, 7, + etc.) one must be prepared to adjust to varying notation.  The following is a list of interchangeable chord symbols:


Major:  M, maj


Major seven:  M7, maj7,
7, ma7  etc.


Minor seven:  m7, min7, mi7,  -7  etc.


Major six:  6, M6, maj6, ma6


Minor six:  m6, min6, -6


Suspended four:  sus4, sus


Augmented:  aug, +


Augmented seven:  aug7, 7aug, +7, 7+  etc.


Diminished:  dim,


Whole diminished:    
7,  dim7


Half diminished:     
7,
, m7(b5)  etc.


Additionally, one must be prepared to interpret a musician’s work.  Many musicians neglect to include modifier parentheses in their charts, due to either ignorance or laziness.  Simply realize this fact and analyze the chord as usual. 


One must also be prepared to decipher chords which are notated incorrectly.  Many jazz musicians use the terms “augmented” and “diminished” interchangeably with “sharped” and “flatted.”  They will say “C with an augmented ninth.”  This is not a correct use of the term, as it results in confusion.  Try to avoid this, but be prepared for this scenario.