Good point Shakedown. I was wondering when someone would bring that up.
The C Mixolydian scale is indeed the 5th (mode) scale degree of the F major scale.
I thought it would be easier to think about it though in terms of the major scale being played (C major in my example - thus F would be the fourth)
What we are talking about (4ths vs 5ths) is the same thing only from two different perspectives.
C is the 5th scale degree of F maj (F(1) G(2) A(3) Bb(4) C(5)). Thus, your point about mixolydian being the 5th mode is true. You would play the F major scale, only C (the 5th) would be your root note (sound familiar?)
but also,
F is the 4th scale degree in C major (C(1) D(2) E(3) F(4)) -- this is what my example was based on.
Basically, the Circle of 5ths is just the circle of 4ths in the other direction.
Aint it neat?
You are absolutely right though, the mixolydian scale is derived by using the 5th scale degree of a major scale. My intention was to make it a little easier to apply on the guitar as opposed to going on an on about music theory nerdiness. Unfortunately, it seems I have just failed miserably in that regard.



