This may start a new thread Murray as my browser wont allow the "quote" marks in "blues scale" on the reply for some reason, -sorry.

You might be confusing the interchange between certain scales that we often use. Think of the blues scale as a pentatonic minor "plus."

It is very similar to the Pentatonic Minor scale except that it has a passing note inbetween the fourth and fifth. The passing note would be an augmented fourth, and it is rarely used as a note to resolve a phrase. Usually, it is used to sort of slur the shift from the fourth to the fifth, and vice versa. Technically this scale could also include passing notes at the major second and major third.

Here's the contruction:

(W+H)-W-H-H-(W+H)-W

W=Whole, H=Half, (W+H)=One and a half or three frets.

No second, flat third, major fourth and sharp fourth, no sixth, and flat seventh.

The pentatonic minor on the other hand would be;

(W+H)-W-W-(W+H)-W

No second, flat third, flat fifth, no sixth, and flat seventh.

And just for fun, the pentatonic Major;

W-W-(W+H)-W-(W+H)

No fourth, and no seventh.

As you can see, the pentatonic minor is near on idetentical with the exception of the one passing note. From experience I can tell you, if you are soloing and are not too sure, use the pentatonic minor, it will work! The use of the passing note may disrupt the feel of sound of the piece if you throw it in where it doesn't really fit. On the other hand, if you can use it, the one note itself can REALLY make a difference if you use it in the right place. :)

You are indeed correct, the blues scale has a six notes in it's construction, therefore making it 'hex-atonic' as opposed to 'pentatonic', unless of course - anybody else knows different :-)

nobbler (Always open to debate)