Five Lessons: Triad Inversions Seventh Chord Inversions Essential 7th Chord Shapes Ninth Chords Slash Chords and Polychords.A first of its kind the At A Glance series pairs an instructional DVD lesson taught by a professional guitarist with a supplemental book for a comprehensive learning experience.Each pack features several lessons pertaining to one topic and the DVD lessons feature on-screen music from a vast array of classic songs.