Chord Wheel : Circle of 5ths
The Interactive Chord Wheel is an implementation of one of
the most basic and significant music theory, 'Circle of fifths' on Android. This app is uniquely
designed to represent the relationship between a scale and a chord.
In the screen of this app, the Circle is made up of several concentric rings, which provides various information. By rotating the 2 rings, inner and outer, the needed information can be got easily.
The outer most ring shows information on the scale such as a tonic, a dominant, a sub-dominant, a relative minor, a relative major, and a progression of the degree. The next outer ring shows a series of note's name ordered by the progression of 5th, and the root note of a scale can be set by rotationg this ring. When rotating the outer ring, the inner ring rotates also. The next ring shows a degree of a note and a diatonic chord in that scale. By rotaing the next ring, a chord can be set. If a note name of the outer ring is touched, then a diatonic chord, of which the root note is the note, is set. Instead of the inner chord ring, a key progression ring can be displayed which is very useful when transposing a song to another key. At the center of the concentric rings, a signiture of the scale is displayed.
In music theory, the circle of fifths (or circle of fourths) is a visual representation of the relationships among the 12 tones of the chromatic scale, their corresponding key signatures, and the associated major and minor keys. More specifically, it is a geometrical representation of relationships among the 12 pitch classes of the chromatic scale in pitch class space. Chord wheel is very useful and powerful tool for a songwriter who analyses / composes music and for a learner who studies music theory.
Both a handset or a tablet are supported. However, it is recommended you to use this app on a tablet larger than a 7-inch for a better usabilty.
- The direction of the circle
- The direction of the key progression on a circle can be set to a clockwise or a counter-clockwise direction by a user.
- Switchable Inner Wheel
- The inner wheel can be switched when it is needed. A chord wheel, a transpose wheel, and a interval wheel are avalable.
- A major scale and 3 minor scale and church modes are available. The scale tones can be distinguished by its background color. A diatonic chord of the scale can be set by touching one of its scale tones.
- Diatonic Scale Chord
- Both triads and 7th chords are supported for each scale.
- Chord Wheel
- Chord wheel is uniquely designed to represent the relationship between a scale and a chord. Most diatonic chords are available. The chord tones can be distinguished by its background color or its mark.
- Transpose Wheel
- For transposing, a ring of key progression can be displayed instead of a chord ring.
- Interval Wheel
- Intervals of notes can be found out easily and quickly. Just switch the inner wheel to an interval wheel.
- Inversion of a Chord
- The inversion of a chord can be played by clicking a button, and also can be seen through the piano view.
- Notation System
- There are various ways of naming note names. In this app, CDEFGAB, CDEFGAH, and Fixed-Do systems are supported. Also, you can set a prefered accidental, a sharp(＃) or a flat(♭).
- Piano View
- Information about a scale or a chord is shown on a 2-octave sized mini piano. It can be played by touching the keys.
- Guitar View
- Information about a scale or a chord also can be shown on a guitar fretboard. It's tunable.
- Colors and Marks
The tones of a scale and a chord are associated with the 7 colors
of the rainbow. For example, the 1st note is red, and the 7th note
Also, marks such as ●, △, ★, ◎ represent that it's 1st, 3rd, 5th, 7th note.
- Clef & Signature
A signature of the scale is showed at the center of rings. A clef
can be set to a treble of a bass.
When the center is touched, user-defined action is performed.
The sound of a scale and a chord can be played. A chord sound can
be played arpeggio pattern or not.
Piano, E.Piano, and Guitar sounds are included. The bundled sounds are recorded in high quality.
Choose a scale type such as a major, minor, etc. then set a root not of that scale by rotating the outer ring. The notes that make up of the scale can be distinguished by the color of its background. Also, a signature of the scale is showed at the center of the rings. A sound of the scale can be played by clicking a play button on the bottom of the screen. If one of the notes that are highlighted is touched, then a diatonic chord of which a root is the clicked note is set.
A figure on the left is a case of D major scale. It represents that notes highlighted by a background color are a member of D major scale. So, we can see some information at a glance that members of a D major scale are D, E, ♭G, G, A, B, ♭D, and D is a tonic, A is a dominant, G is a sub-dominant, and a relative minor scale of D major is a B minor.
Choose a chord type such as major 7th, dominant 7th, etc. The root note of a chord can be set by ratating the inner ring. The notes that make up of the chord can be distinguished by the color of its background or its mark. A sound of the chord can be played by clicking a play button on the bottom of the screen.
From the figure on the left, we can see easily that the IIm7 chord in a D major scale is Em7. Also, we can see some infrmation at a glance that the members of the Em7 chord are E, G, B, D.
When you want to find a scale of a music, set the type of a scale first, then rotate the outer ring until every chord/note is highlighted. Or in contrary, you can start it by setting the root note first.
Like the figure on the right, inner ring can be replaced to a ring of
key progression instead of a chord ring. This feature is really
useful when transposing.
For example, in case of transposing a D Major scale to C Major scale, set the outer ring to D and the inner ring to C, like the figure on the right. Then, we can see that an A chord of a D scale have to transposed to a G chord in a C scale, and an E chord of D scale to D chord in C scale.