Remember: all 12 notes of the Western temperament (C c# D d# E F G g# A a# B) stand in relation to each other by means of intervals. These intervals are static. A guitar's tuning is, however, prone to change in certain situations. What I am trying to say is that, while the tuning of the guitar might change, the interval between whatever note an open string represents and a given fretted note will always be the same. It is for this reason that I advice you to learn which intervals are found on which fret.
Let's start by identifying the most important intervals:
- The notes on the 12th and 24th frets will always be its octave.
- The notes on the 7th and 19th frets will always be the perfect fifth of the note to which the guitar string is tuned to.
- The notes on the 5th and 17th frets will always be its perfect fourth.
- The note on the 2nd and 14th fret will always be a major second.
- The note on the 3rd and fifteenth fret will always be the minor third.
- The note on the 4th and 1(six)th fret will always be the major third.
- The note on the 10th fret will always be the minor ninth.
By approaching the fretboard in this almost mathematical fashion, you won't be confused by a guitar tuned to something other than standard tuning.
Perhaps this approach will prove helpful in your case. Even if not, you can still see how knowing a bit of music theory can prove useful at times.
About the Author:
By Miguel Marquez. I invite you to check out my YouTube channel for some of the stuff I'm doing.