
Circle of fifths and number theory - lelf
http://www.johndcook.com/blog/2009/10/02/circle-of-fifths-number-theory/
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chris_wot
I am a total musical dunce. I had to look up what a chromatic scale is. Turns
out, it's this:

[http://upload.wikimedia.org/wikipedia/commons/d/d0/Pitch_cla...](http://upload.wikimedia.org/wikipedia/commons/d/d0/Pitch_class_space.svg)

If you ignore the semitones (the sharps - # - and minors - b) if you go around
the circle 5 or 4 notes at a time it turns out you eventually get back to the
note C.

Pardon me if this all sounds very dull and obvious, but something seems to
have been missing in my education. This actually starts to open up a new world
for me... Which doesn't happen very often! Similar things happened when I sat
down to understand exactly what sine, cosine, tangent, cotangent, secant and
cosecant were on a circle.

I suspect the same will happen when I finally understand the basics of
calculus...

~~~
gtani
there's lots of ways music students remember the circle clockwise and
counterclickwise, beginning with key signatures for C major (no sharps/flats),
G and F (one sharp and flat) etc. Violins thru cello are tuned in fifths;
double bass and the lowest 4 guitar strings in fourths (E-A-D-G from lowest to
highest pitched).

If you want to read more, there's these little $6 books

[http://www.halleonard.com/product/viewproduct.do?itemid=3309...](http://www.halleonard.com/product/viewproduct.do?itemid=330968&subsiteid=66&)

[http://www.barnesandnoble.com/listing/2690028887554?r=1&cm_m...](http://www.barnesandnoble.com/listing/2690028887554?r=1&cm_mmca2=pla&cm_mmc=GooglePLA-
_-Book_5To14-_-Q000000633-_-2690028887554)

