Hi, I am interested in writing songs for the guitar. I have been playing classical guitar for about tens years and started with accompaniment guitar a couple of years ago. I studied 'solfege' (I guess it is called music theory in English?) a while ago and don't remember most of it. I am interested in writing some songs for the guitar or as well as better understanding how songs are written and why those chords go together. Does anyone know of a good book that I should buy?