The idea of \u200b\u200bthis method for guitar was born from the desire to gather and share all the music encountered on the crossroads, since our studies of classical guitar and composition. These paths brought us improvised music, Indian music, Arab-Andalusian music, blues, pop-rock, funk, jazz, but also French, South American, Cape Verde and Caribbean songs. In developing this method, we have constantly sought to respect the styles of music. Special emphasis has been given to the preponderance of rhythm in music, regardless of style. This naturally led us to include guitar parts, so-called rhythmic, or accompaniment and thus to talk about chords and harmony. All the pieces are composed of a main melody, played by the first guitar, a second guitar that plays arpeggio harmony, and sometimes we have added a third, or even a fourth guitar, to introduce you to a set of guitars set. To make the subject of harmony clearer, we have added to the seven notes, or degrees in the scale, the seven colors of the rainbow. And so as not to run out of creativity, we offer some ideas for you to dare to improvise with enthusiasm.