Here is what Chick Corea said about the chord symbols in his book, "Chick Corea - Beneath The Mask".
http://www.amazon.com/Chick-Corea-B...r_1_10?s=books&ie=UTF8&qid=1384534566&sr=1-10
"P H I L O S O P H Y
I use chord symbols as a direct invitation to the player to improvise and add notes and embellishments.
The chord symbol indicates the scale that I intended to go with the melody.
The voicing of a chord can be written out note-for-note, or it can be improvised by the player – as when the part has a chord symbol and melody note only.
I find it confusing to try and ‘write out’ a voicing by only adding extra numbers and signs to the chord symbol.
Chord symbols that indicate the first four notes in a chord (bottom to top) are usually sufficient to give all the information that the player needs, quickly and at a glance. (For example: C = C root, E third, G fifth, B seventh; G7 = G root, B third, D fifth, F seventh.)
I never include in the chord symbol altered notes that are in the written melody, (i.e. if there’s a C# written in the melody and it’s a G7 chord, I never add “b5” to the symbol, as it’s already written in the melody).
When there’s an “important” note that the voicing needs, I first try to write the note before attempting to add it to the chord symbol.
Most “altered” notes are “passing tones” anyway – and if a little extra time is taken to write them – often a nice counter melody begins to develop.
I use chord symbols for a quick appraisal of the harmony and scale of the part it applies to. They invite improvisation.
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A P P L I C A T I O N
1) Triads and chords without 3rds or 7ths are called by just the letter of the root – i.e. – C = C Major triad; E = E Major triad, ect.
2) The 7th degree of a chord is usually the highest number given in the symbol. The 9ths, 10ths, 11ths, etc. – aren’t put in the chord symbol, as they’re usually in the melody line.
3) The only time other notes in the chord are added after the basic root, 3rd, & 7th (i.e. Dm7) is if the added notes are not in the melody line of that bar and are needed for the sound of the harmony. A b9 or b5 is sometimes added.
4) The form of the chord symbol:
- ‘m’ is used for minor : … Dm7, Cm
- Caps are used for all root notes: … C7, F#7
- ”b” and “#” are used instead of “-“ and “+”: … Db7, Bbm#5
- Other than the basic root, 3rd/7th construction, added notes are done in smaller size and above: … Cm7b5, C7b9
- “^” is used for “Major 7th”"