So, it's a really very comprehensive and well-structured book... but like all books integrating scales. As with the book on chords, I regret that there are no references to famous pieces of music. Note, I'm not saying to find the solos of the pieces... but simply to reference "this scale is used in the piece 'tralala'". That would have allowed, it seems to me, to work on these scales according to one's musical inspirations (which is always more motivating, right?) - So, as always, the book looks nice on a bookshelf, but the collection quickly becomes expensive (understand, it seems expensive to me for what it is - even if there is no deception about the merchandise!)