I strongly recommend not only Fretboard Wizard but also Tony's Acoustic Challenge. Permit me to be word.,y here. I am a physician and each day I have to explain processes to my patient. I draw diagrams, schematics and explain basic functions of organs. My patients have virtually always said that the fact that they now UNDERSTAND the basics, the mechanisms, their diagnosis and treatment makes sense. That is Tony's basic philosophy. Can you understand the basic science, math and reasoning behind the guitar. I love that her helps us neophytes out here understand guitar theory in bite sized chunks, bit by bit, day by day. It has made an incredible difference. This is a monster giant step for a guy whose previous guitar experience was looking at chord diagrams in his Mel Bay collection and trying to mimic them and then giving up. TAC and Fretboard Wizard has been the best thing to happen to this guitar geek.