The CAGED system is a method for mapping out chords, not scales. But, you can then mix these chords with scale patterns. I show you how to get started with this in Fretboard Theory Chapter 4: Five is the Magic Number. Later in Chapter 7 I teach more about applying scales.
You can mix in the CAGED forms with any scale pattern, it just depends on what chords you’re playing over. If you’re playing over a progression in E major, and E major is the root chord, then you can play E major pentatonic and/or the full E major scale. You can also use E major CAGED chord forms and arpeggio patterns. When the chord changes, to A or B or something else in the key, you can use the CAGED chord forms and arpeggio patterns that correspond to those chords (still along with E major pentatonic and/or the full E major scale). Get it? Let me know.
To learn more about music theory for guitar, including scales, chords, progressions, modes, and more, sign up for a free preview of my Fretboard Theory books and DVDs by using the form on this web page.
Play Until Yer Fingers Bleed!
Mr. Desi Serna