Selecting the form of chord symbol is sometimes determined by the style of music. Most pop,. rock, rhythm & blues, country, funk etc., will use smaller chord forms of chords, maintaining a three or four note level of complexity. More sophisticated styles will utilize all forms up to and including the 13ths and altered versions of chords.
Often, in the case of the melody providing the 9th or 13th of a chord, you will find the chord symbol shown in a smaller form, but combined with the melody, producing the actual chord which could then be a 9th or 13th chord.

Chord symbols can be made more modern sounding by adding extensions (such as the different forms of 9th, 11th and 13th) to create a more sophisticated stylistic impression, or by using basic triads to make the harmony more basic sounding and less an important factor of the music.

Chords tell a musician basic information, such as whether the harmony functions as a diatonic resting chord or active chord. They also specify if the chord is chromatically altered. Chord symbols are not played literally. By this we mean the performer takes in the basic information and then in the process of creating their  ‘part’ or musical solution, will interpret the chords to best fit their specific instrument in context to the orchestral combination of instruments playing.

Along with specifying the diatonic and chromatic diatonic and chromatic chord types, information regarding how many beats each chord is ‘in force’ or to be used is accomplished by using slashes or ‘virgules’ to denote how many beats is assigned to each chord. The slashes, ( /  /  /  / ) will represent each beat of the 4/.4, 3/4 or specific meter of the music. The conventional meaning of the slashes is not to literally play even quarter notes (although it is often interpreted that way in ‘rhythm guitar’ playing), but rather to allow the player on guitar, keyboards or improvising to devise their own rhythmic sentences. In this ‘common’ notation of rhythm, the player plays rhythms that identify the musical style, tempo or feeling desired. A lead sheet is not an arrangement. It is simply a guide part that the player converts into his finished rendition of the music. Example 1 demonstrates slashes used to represent straight ‘time, while Example 2 illustrates rhythmic slashes dictating the precise rhythm that the play would play with the chords. They are typical of concerted or ensemble rhythms found when the entire group or band play the same rhythm.

In this sense all components are looked at in a very flexible manner. For instance:

As chord symbols per se do not communicate an ‘arrangement’ for the players, we have just discussed how each player fashions his own part from the guide part instructions that the chord symbols and rhythmic slashes tell him or her. There are however, specialized chord symbols that give the player more specific information resulting in the lead sheet beginning to control how the player interprets the symbols.

The most commonly found specialized variation is the use of chord inversions. They tell the player to play the chord as usual, but to place a given note in the lowest voice on guitar or keyboards. They also instruct a bass player as to the specific note of the chord to play.

As a chord inversion means to invert the tones of a chord into a different permutation or position, the notation of a chord inversion is important to understand. It is also critical to understand why a chord inversion would be used, as opposed to defaulting to the obvious root in the bottom voice at all times.

To communicate to the player the note of the chord to play in the lowest voice, write the basic chord symbol as usual, followed by a diagonal slash ( / ) and the inversion tone desired ( C/E ). On occasion you will also find it written C/3. One version writes the specific tone, the other version writes the chord function (3, 5, 7).

Inversions are limited to the 3rd, 5th or 7th of a chord, as the higher extensions would sound like a fundamental part of the chord resulting in making the voicing sound like a incorrect chord. Any voice placed in a lower voice will tend to sound like a fundamental part of a chord.

The reason to utilize inversions is to control the bass voice to achieve a horizontal, melodic sounding voice. The result is that the outside voices (highest and lowest) create two horizontal melodies moving against each other. This makes a more sophisticated impression and sounds more musical than always using roots in the lowest voice. Inversions are more typically used on ballads and slower tempos. The following examples illustrate the typical use of inversions in different contemporary styles.

Another notation device used to better ‘control’ the interpretation of the chord symbols is called a polychord. As ‘poly’ means more than one, the definition of a polychord is to superimpose one chord on top of another. The upper structure is usually a triad shape, however it can also be a 4-part chord form. The correct chord symbol for this relationship is to place a chord symbol over a horizontal line, denoting to play the upper chord over the lower chord.

This symbol instructs a player to play the upper triad shape over the lower chord symbol. The lower is the basic chord. Any chord can be turned into a polychord, thus there is another entire system of polychord symbols that are alternatives to all the conventional symbols. It is an involved and sophisticated harmonic creation and is typical of jazz, standards, fusion, jazz/fusion and more compositional styles of contemporary music.

In the orchestration of a polychord, a keyboardist would play the upper shape in their right hand and some interpretation of the lower chord in their left hand. A guitarist would play the upper triad, leaving the lower chord to be played or implied by the bass part, the keyboards, etc. The guitarist can also play the upper triad shape plus one or perhaps two of the tones from the lower chord. In orchestral music you hear polychordal combinations where in the trumpets play the upper shape, the low brass of trombones, French Horn play the lower chord, etc.

Another specialized type of chord symbol is found in contemporary music that is based on Modal harmony. The most prevalent type of modal harmony is called ‘static modes’. This means that a song or composition is based on many measures of one mode, and although it may shift to a  new mode in a new key, it is unlike conventional chord symbols. It is more like modal scales changing from one to another.

When playing or arranging music in static modes, a harmonic definition is required. That definition is achieved by using the IV - V triads of the major scale from which the mode is derived. As a case in point, a D Dorian mode is based on moving from the 2nd tone of a Cmajor scale ( D )

up an octave to the next ‘D’. As the mode is derived from the tones of the Cmajor scale, that is the source and can be referred to as the Relative Major of D Dorian. The IV - V triads of the C major scale are F and G major triads. Any tone of these two triads can be placed on top as the melody by inverting the triads to position the triad in this manner. As there are three possible melody notes from each triad, the combination of the two triads will therefore harmonize six of the seven melody notes of a major scale.

This relationship can be notated and communicated to players by using a special chord symbol that shows the IV and V triads placed over a horizontal line. Below the horizontal line is either the basic I chord of the mode, or the tonic of the mode. Below are the Modal Alternating Triads for all the modes based on the ‘C’ major scale.

The dash between the IV and V triads can be thought of as a double arrow, in that it represents that you can move from either triad to the other, in an alternating fashion. If graphically written out, it would look like:

Take each of the modal alternating chord symbols shown in Example 7 and play them on your keyboard or guitar. You will recognize that ‘sound’ as the one you hear all the time, particularly on current funk recordings as well as in  jazz music. This is how it is notated, and when the players see this, they ‘do their thing’.

Here are some important guidelines to try to remember when writing chord symbols:

Hope you have found some useful and perhaps new information in the above, and remember, one way to make good musical friends is communicating clearly. Everything gets done better faster, more musically and with more energy.

Good Luck to you

Dick Grove