Most guitarists see G7 as just "a chord." Gabis teaches you to see G7 as a force pulling towards C. Once you understand that, you can substitute G7 with Db7 (the Tritone Substitution). Suddenly, your blues progression sounds like jazz fusion.
Gabis breaks down the melodic minor, harmonic minor, and natural minor not as separate entities, but as functional modes. He shows you when to use a major IV chord in a minor key (Dorian) and when to use a diminished viiº (Harmonic Minor). This unlocks improvisation for solos. Libro Armonia Funcional Claudio Gabis Pdf
Because the search for the free PDF is so frustrating, many musicians give up. Don't. Here is your action plan: Most guitarists see G7 as just "a chord