[Dixielandjazz] Circle of 5ths

[Tom Belmessieri]

To anyone who is interested in this stuff:

It is referred to as the circle of fifths because, as one goes around the 
circle in either direction, a sharp or a flat is added to that key, which is 
a fifth above or below the preceding key.

i.e. Clockwise from C is G, D, A, E, B, F#, C#.  Each is a fifth above the 
preceding key and a sharp is added to each successive key.  
Counter-clockwise from C is F, Bb, Eb, Ab, Db, Gb, Cb.  Each is a fifth 
below the preceding key and a flat is added to each successive key.

A key signature will not contain more than seven sharps or flats because 
it's not necessary.  There are only 12 tones in a chromatic scale, hence 12 
tones in which a piece can be played, even though there are more than 12 key 
signatures.  For the sake of ease or convenience, a piece would probably be 
written in Db instead of C# because it has 5 flats vs 7 sharps.  Same pitch, 
different key signature.

Those who contributed references to equal temperament as applied to this 
concept are correct.  We could not have the "circle" of fifths without it, 
but a spiral indeed.  The chromatic scale of any key is not perfect.  It 
cannot be.  A piano, for example, can only be tuned perfectly in one key.  
In order for it to be useful in any key, equal temperament must be employed. 
  That means each note is the same "relative" distance in frequency from the 
one next to it.  The fourths become a little stretched, the fifths become a 
little narrowed, etc.  The variance is negligible to the ear but it makes 
enough of a difference to render the instrument playable in any key.  The 
same holds true for any musical instrument in the way it is made.


Note to John Farrell: I guess tangents make these communication strings more 
interesting.


Tom B.
-----------
>From: "John Farrell" <stridepiano at tesco.net>
>Reply-To: stridepiano at tesco.net
>To: "DJML" <dixielandjazz at ml.islandnet.com>
>Subject: [Dixielandjazz] Circle of 5ths
>Date: Tue, 8 Nov 2005 19:21:01 -0000
>
>Some of the responses to this thread have been interesting. One, Steve
>Barbone's, suggested that if by now I did not know what a circle of 5ths 
>was
>then I must be suffering from arrested musical development - in fact my
>original question to the list was not what it was, but why it was it so
>called when the intervals employed were 4ths.
>
>Another suggestion was that "5ths" indicated the number of chromatically
>ascending notes required to progress to the subdominant key (five).  A 
>novel
>notion but I don't buy it.
>
>Several listmates have said that the circle of 5ths is also known as a
>circle of fourths, the latter according with my contention. Others pointed
>out that the 5th refers to the relationship of the dominant note, while 
>this
>has an authoritative ring it seems to me to be an unnecessarily clumsy
>system of identifying a simple harmonic progression.
>
>Had the notorious Joe McCarthy been musically inclined he might have 
>branded
>some of his victims The Circle Of Fifths.
>
>John Farrell
>http://homepages.tesco.net/~stridepiano/midifiles.htm
>
>
>
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