Modern Guitar Method Grade 4, by Mel Bay. Now clearly at the intermediate level, Grade 4 begins by introducing the E major scale in three octaves plus the principal chords in E major. The C# harmonic and melodic minor scales are introduced followed by a wealth of carefully arranged solo and duet study material in various keys in the fourth, fifth, seventh, and ninth position. Three basic shapes for major and minor chords are reviewed through chord studies in various keys.