under theory behind major chords, the example you give shows how you got to the "F" chord I can see that but under the F scale if I need more chords, what kind of interval would I use. or to put guitar chords to a song if I wanted to make up chords for the song. is there an interval set for that I really appreciate you guys you have been a great help to me I'm 67 years old never had any music ever. until this summer when I got a $10 mexican guitar at a garage sale thanks again. I hope you can see what I'm asking. Jim