The circle of fifths figure
The twelve notes in fifths order round the outside and in pitch order on the wheel inside, home on top in both; a run of fifths stands on a capsule, and a spoke from each note to its wedge shows the two orders crossing.
Twelve fifths visit every note once and come back where they started. This figure draws that circle the site's way — two rings of the same twelve notes, ordered differently — and it is the figure of the circle of fifths essay and of the pentatonic and mode pages.
What it shows
Two rings, the same twelve notes. The outer ring is the notes in fifths order, each a fifth above the last as you go round. The inner ring is the note wheel: the same notes in pitch order, semitone by semitone. Home is on top in both — the site's wheel rule; the textbook's fixed C is not used here, and where the essay counts sharps and flats it counts them from C in the text.
A run of fifths stands on a raised capsule along the outer ring: five in a row, seven, or all twelve. Home shows its name; the other notes in the run show their degree, spelled the way the set spells them, with the name small outside the ring. A note outside the run is a small gray disc.
A spoke runs from every note in the run to its wedge on the wheel. Because the rings order the notes differently, the spokes cross — and those crossings are the whole figure: fifths order against pitch order. A note that joins the run draws its spoke in after its wedge opens.
How many fifths sit below home in the run is what names the set. Five with none below is the major pentatonic; five with three below is the minor. Seven reads lydian, major, mixolydian, dorian, minor, phrygian, locrian along the run — brightest to darkest — depending on where home stands in it. Under the drawing the set is written out in scale order with each note's semitones from home.
What you can do
- 5 · 7 · 12 choose how many. From twelve, seven is the major scale and five the pentatonic; going between five and seven keeps major with major and minor with minor.
- Tap a note inside the run, or its chip in the row under the drawing, to make it home. The run stays where it is and the wheel spins: the same notes, a different place to stand — that is a mode. A seven's row labels the modes; a five's names the major and minor pentatonic and dims the three the site doesn't stand behind.
- The root row above the drawing moves the run to a new key. One note leaves the capsule, one joins, and the run slides round the circle.
- Hover shows and changes nothing: a spoke brightens and its wedge marks; a gray note gets a dashed spoke to where it would sit.
- ♪ plays the run round the ring in fifths order, rising and folded back into range, each glyph pulsing in turn — then the same notes round the wheel in scale order, each wedge in turn. The two orders, heard.
Nothing outside the run is tappable. The state is in the address — #circle=G.7.1 is G major, home written without a sharp sign (Gb, never F#, since a second # breaks a link) — and the essay's prose sets states between its headings, including a five inside a seven, drawn as an inner capsule.
Where it appears
Pinned under the essay; on the circle of fifths page with all twelve; on the pentatonic, mode and major modes pages, where it follows the root of the instrument figure above it; and, bare — the rings and ♪ alone — in the walk that opens Why the major modes, one fifth at a time.