In Intervals, the Fretboard and the Strings, I showed you how knowing intervals helps you to gain guitar mastery. Knowing a bit about intervals helps you further reveal the secrets of the fretboard.
Any tone on the 7th fret of a P4 string (E, A, D, G) produces a P5 for that string. In Riptide Guitar, we think of the string (B) as being tuned down a half step from the G string. So you need to move up one fret to the 8th fret to get the P5 for B.
If you notice, the tones at the 7th fret starting on "chin" E (aka low E) are the tones of the open strings starting on B and rotating around to G. Wow, right?
