If you are on C and move 1 step or 1 fret that is minor 2nd, in other words it is a flat D or sharp C. Move 2 steps or 2 frets your on Major 2nd or D. If your on B and move 1 step or 1 fret you are on minor 2nd or a flat C. But going to 2nd fret or 2 steps make it a C sharp. I think it is important to know the scales of each note on the fretboard to understand this. What are your thoughts on this? I'm now on Guitar Fundamentals 2 on intervals.