CRGU Solo 7 - major without changing key

[Quark]

In BGU we learned that the key used to solo with the major scale should be be in line with the chord:
e.g. for a blues in G, I play major G over the I cord, but then typically switch to minor G for the IV and the V cord (or potentially play C major over VI and D major over V).

However, in CRGU solo 7 we play major G consistently over the D, C, and G chords (=V / IV/ I of G)... and it sounds great! Why is that working? What am I missing?
Thanks
Marc

 

[Paleo]

In CRGU you are playing all Major Chords, no 7 chords.

If all the chords of a progression are in the same key, you can play the Major Scale over all the chords.

A blues progression is a different animal. You typically have all Dominant 7 chords.

Dominant 7 chords are V7 chords in a key.

Each 7 chord in a blues progression is actually the V7 of a different key.

G7 is the V7 in C.
C7 is the V7 in F.
D7 is the V7 in G.

So each chord change is technically a key change.

You can play G min pentatonic over the whole thing and it will "work".

Griff often suggests G Major pentatonic over the G7 chord.

Or you could play G minor pentatonic over the G7, C minor pent over the C7 and D minor pent over the D7.

Or G Mixolydian over the G7, C Mixolydian over the C7 and D Mixolydian over the D7.
(Mixolydian rather than Major because of the b7).

Again, if the chords are all within one key you can play the scale of that key over the entire progression.

A Blues progression isn't all in one key. We call it a I IV V for convenience, but it's actually a V7 V7 V7 or treated as a I7 I7 I7.

 

[Quark]

I had never realized that the 7 chords along a blues progression are actually key changes. Thanks a lot, this clears it up.
... guess I should study a bit theory before going into Modes

 

[Paleo]

.. guess I should study a bit theory before going into Modes

Modes will be more in line with your CRGU example, which is in Mixolydian.

You will always be able to stay with one scale as long as the song stays in one mode.

Best of luck.

 

[Griff]

@Quark there is, in fact, an example in Modes Unleashed specifically to address this (the Mixolydian example.) I believe the chords are even the same.

If you want to have some fun and go a little Southern Rock on it, use G major over the majority of it and then switch to G minor pentatonic for a bit. Listen to the 2nd guitar solo in Sweet Home Alabama and about 2/3 of the way through, he goes up to the high G and uses the minor pentatonic just for a bit. It's a nice change of pace.