First, let me apologize for resurrecting an oft-discussed topic, but the fact is that despite "all my learnin', towards the bad I kept on turnin'."...or at least my soloing did.
I'm probably the poster child for how a little bit of knowledge is a dangerous thing, but my question is WHY is G Mixolydian a better scale for this song?
Here's my modest understanding of theory (culled from piano lessons as a kid, a single college class on music theory, and nearly thirteen years spent reading this board):
The C Major scale is as follows:
C, D, E, F, G, A, B (ad nauseum, infinitum, or your latin word of choice)
So I look at these as "available" notes for a solo.
A standard major scale is also known as the "Ionian". The "Mixolydian" scale uses the same notes as the major/Ionian scale but starts at the note a fifth above. So, if I haven't memorized the pattern of whole/half steps for a Mixolydian, all I need to do is look to see what note is a fifth lower and then use the notes from that Major/Ionian scale. So for a "G Mixolydian," I ask myself "what note is a fifth lower than G?" and my answer is C. So a G Mixolydian would use the same notes as a C Major/Ionian, but instead of starting at C, we start at G, like this:
G, A, B, C, D, E, F (ad infinitum)
Same available notes, different order.
Because I see this from the perspective of a keyboard, I'm not seeing individual scales, but instead a continuum of "available" notes from the lowest of frequencies to the highest. To me, using the terms Ionian, Dorian, Phrygian would really only come into play if someone took a snapshot of the keyboard and asked me to describe what I saw. If the key furthest to the left were the root note, a C in our example above, if asked, I could accurately describe it as a C Major or Ionian scale. Similarly, a D Dorian if the first note were a D. Since I'm a visual learner, and others might be too, I'll try to depict this visually:
[The lowest white key on a piano is an A, so that's where I'll start my reference from]
ABCDEFGABCDEFGABCDEFGABCDEFG - Available Notes
ABCDEFGABCDEFGABCDEFGA - B Locrian
ABCDEFGABCDEFGABCDEFGAB - C Ionian
ABCDEFGABCDEFGABCDEFGABC - D Dorian
ABCDEFGABCDEFGABCDEFGABCD - E Phrygian
ABCDEFGABCDEFGABCDEFGABCDE - F Lydian
ABCDEFGABCDEFGABCDEFGABCDEF - G Mixolydian
ABCDEFGABCDEFGABCDEFGABCDEFG - A Aeolian
So how do you know when someone is playing in G Mixolydian as opposed to C Ionian? They're all the same notes, so is it a matter of examining the fingerings used by the musician? Or is there something that I'm missing in my Ionian-centric thinking?
What's more, we still haven't addressed the "why" behind G Mixolydian being the recommended scale.
You mention that it's better for "resolving on that G."
I have an equally limited understanding of resolution. I know that resolving from the fifth to the first is pleasing to the ear. If we're talking individual notes, that's the jump from G to C. If we're talking triads found within a major scale, that would be G major -> C Major. If we use the I, ii, ii, IV, V, vi, vii Roman Numerals, we're talking V->I. Sounds great. Sounds complete. Could easily be the ending of a song (which I believe is why it is called a "Perfect Cadence.") Sounds better than the resolution of a fourth to a first (F -> C, F major -> C Major, IV->I, known as an "Plagal Cadence.")
So what is meant by "resolving on that G?" From the major triads found in the song, I'd say that the song was in the key of C. With C as a root note, G major would be the V chord. So wouldn't the resolution actually be G -> C? Or are you saying that you like to end your riffs/phrases on the G note? Or perhaps that you like ending them when the background chord is a G major?
Could someone please help me out here? I feel like I can grasp the theory, but that putting it into practice is beyond me. (My "solos" consist of arpeggiating the underlying chords far, far too often).