Re:Guitar Decomposed: 5. Mutating the Third
by parenthesis on Friday May 29, 2020 @06:41AM
(#23348398)
If you think in terms of modes, then using a sharp 4 in major you can think of as lydian (the 4th mode of major) or lydian dominant (has a flat 7 too, the 4th mode of melodic minor). In minor, there's lydian minor (the 4th mode of harmonic major).
Major but with a flat 7 is mixolydian (the fifth mode of major). It is everywhere in popular music.
My favourite thing at the moment is major 7 sharp 5 chords (or an augmented triad with also a major 7th). These chords arise in harmonic and melodic minor (in both cases chord 3), and in harmonic major (chord 6). But they also sound great as substitutions for what is 'supposed' to be a major 7 chord.
I usually compose with a Major or Minor key in mind, but it's kind of a reference and not a be all end all. I like sharp 4's which work great usually and don't fit in either key. A flat 7 sounds great in a major key too, usually. I agree with you mostly, and i am annoyed by people who are adamant about the rules of a key, but it helps me to have a key in mind to both play and compose, even if i break the rules of it.
I find improvising on piano / guitar is nearly impossible if you don't know the key, even after many years of playing both.