Matching is the process of analyzing the notes present in a chordshape and deciding what chord (or chords) it makes when played. ChordWizard does this for you automatically.
For example, on a guitar in standard tuning, the chordshape 320003 makes the chord Gmaj. ChordWizard has to go through a few steps to work this out, but the result appears instantly.
This topic describes what really goes on with matching. For simplicity, all examples use the guitar in standard tuning, but the same process applies to all instruments.
Notes of a Chordshape
The tuning of the instrument plus the chordshape itself determines what notes are present. With our example above:
| 3 | => | G |
| 2 | => | B |
| 0 | => | D |
| 0 | => | G |
| 0 | => | B |
| 3 | => | G |
we get the notes G-B-D (the repeated notes can be ignored).
These three notes are then compared against the notes that are produced by all known chords. That is, from all the chord types that ChordWizard knows about, using any of the 12 possible root notes. Something like this:
| Am | = A-C-E | => fail |
| Bbm | = Bb-Db-F | => fail |
| ... | ||
| G#m | = G#-B-D# | => fail |
| Amaj | = A-C#-E | => fail |
| ... | ||
| Fmaj | = F-A-C | => fail |
| F#maj | = F#-A#-C# | => fail |
| Gmaj | = G-B-D | => MATCH |
Multiple Matching Chords
Usually you will end up with one clear result from the chord matching process, as in the example above for Gmaj. However, you may often find more than one matching chord comes up in the results.
For example, the two chords Em7 (containing E-G-B-D) and G6 (containing G-B-D-E) are made up of the same four notes.
Any chordshape which produces these four notes has both Em7 and G6 as matching chords. Both of these chords match the four notes exactly, but one of them is always a better choice.
ChordWizard decides which chord match is closer by comparing the order of the pitches of the notes in the chordshape with the order of the notes for the chords in standard inversion.
The lowest pitched note present plays the most important role in deciding the interpretation of the notes. In the example above, the chordshape 020000 has the note E on its bass string, making it sound closer to Em7.
| 020000 | => | E-B-D-G-B-E |
| Em7 | => | E-G-B-D |
| G6 | => | G-B-D-E |
By contrast, the chordshape 320000 contains the same four notes, but has the note G on its bass string, making it sound closer to G6.
| 320000 | => | G-B-D-G-B-E |
| G6 | => | G-B-D-E |
| Em7 | => | E-G-B-D |
Inexact Matching Chords
ChordWizard can also show inexact matches for a chordshape. These occur where a chordshape contains most of the notes of a chord, but has some missing.
For example, with a chordshape that contains the notes C-E-G, the exact match is Cmaj, but it could also be an inexact match of Am7 (normally containing A-C-E-G), but missing the A.
Inexact matching chords are especially important if there are no exact matches for a chordshape.
For example, the chordshape x3232x is comfortable to play, makes a great sound, and is commonly used in rock and jazz. However, it has no exact matches with any of the standard chord types. It is actually closest to a C7b9 chord (which consists of C-E-G-Bb-Db), but it misses the G note.
By comparison, the chordshape x32323 has C7b9 as an exact match, since it contains all these five notes. Play the two chordshapes after each other and you will notice that although the new one sounds fuller, it has the same mood which was already strongly there in the first.
In this case, the missing note of the chord was the 5th degree, which can often be dropped without greatly changing the overall sound. By contrast, any of the minor chords without the flat 3rd degree is meaningless, since it is precisely this degree which determines the minor character of a chord. For more details see Required Degrees.
ChordWizard allows you to control, for each chord type, which notes may be missing (optional degrees) for matching chords, and which notes must be present (required degrees). All these options can be found in the Chord Types page of Library Options.
Matching chords are always listed by ChordWizard in order of exactness. That is, exact matches first (if any), then matching chords missing one note, then two notes, and so on.
Power Match
Sometimes you may have a chordshape which sounds good, but shows no matching chords. Often this is because you are using a library at beginner or intermediate level where the less common chord types are deactivated for simplicity.
It could also mean that the chordshape is making an unusual chord, which is not one of the standard chord types.
In either case, ChordWizard provides the Power Match tool to help you adjust your settings and find appropriate matching chords.
Power Match uses a two step process. First it tries to find suitable matching chords from among those it already knows about (including deactivated chord types). If this still fails, you can create a new chord type to fit the chordshape you are designing. This new chord type will then be available for analyzing other chordshapes in the library.
Matching Parameters
ChordWizard provides a great deal of scope for you to customise the matching process to your preference, with settings located in the following areas.
The Chord Types page of Library Options allows you to activate, deactivate, add or modify the chord types which are examined during matching.
The Indexing page of Library Options allows you to select the maximum number of matching chords per chordshape, and the how exact the matches must be.
See Also
