[Harp-L] Questions re: blue notes and micro-tonality

["John F. Potts" <hvyj@xxxxxxx>]

	I am trying to learn more about the correct pitch of the "blue  
notes" in traditional blues tonality.  I have not been able to find  
much reference material on this subject. The blue notes in the blues  
scale are the flat 3d, flat 5th, and flat 7th.
	As i understand it, in traditional blues tonality the flat 3d is  
supposed to be played a quarter tone flat, and is called a "blue  
third."  BUT, that same note is also the flat 7th of the IV chord  
and, as I understand it, when played as a flat 7th that note should  
be played a half step flat in traditional blues tonality, NOT a  
quarter tone flat.
	Okay, a "blue third" is a quarter tone flat. QUESTION: What is the  
correct traditional blues tonality for a "blue seventh"?  Is it a  
true minor 7th (half step flat) or is it played 3/4 step flat, like  
Little Walter did by bending draw 5 down a quarter tone on some of  
his better known tunes?
	  ANOTHER QUESTION: What is the correct traditional blues tonality  
for the "blue fifth"?  I have seen one reference that suggests the  
"blue fifth" (flat 5th) is played a quarter tone flat in traditional  
blues tonality, like the "blue third."  Is this correct?
	The micro-tonality of the blues constitutes such a fundamental  
expression of  emotion in the blues idiom  and is readily played on a  
diatonic harmonica.  How far flat a blue note is bent, and whether or  
when the flatted blue note is released to resolve into the major  
chord is an important (and very cool) aspect of playing blues on the  
diatonic harmonica. But although i think i understand the nature of  
the "blue third"  I am interested in whatever  any of you can tell me  
about the proper traditional blues tonality for the "blue seventh"  
and "blue fifth."  Please enlighten me with more detailed information  
on this topic .  Thanks.
	JP