Watch the Where Are The Notes? online guitar lesson by John Goldsby from Upright Bass Handbook
In this lesson, we'll find some important harmonics that we can use visual and aural landmarks on the bass. Some traditional bass methods start at the very bottom of the instrument and tediously work up to the high register. I'm going to show you some higher positions first by dividing the string into half, thirds, and quarters. We'll learn how the string vibrates at these harmonic nodes, and how you can find notes and positions using harmonics.
A harmonic is a bell-like tone that you get when you lightly touch a string with your left hand finger and pluck it with your right hand, rather than pressing the string down to the fingerboard with your left hand. The easiest harmonic to find is the octave.
Divide the String in Half
If you eyeball the bass, and divide the string in half, you'll find a harmonic which is an octave above the open string. On the G string, you'll find a high G harmonic at the halfway point in the middle of the string. This is like the 12th fret on an electric bass. I can find these harmonics on every string in this position: G, D, A, E. If you're going to tune with an electronic tuner, these are good notes to play, because the tuner can pick up these frequencies easier than the low open strings. The harmonic in this location is the same pitch as the note under it on the fingerboard; I can play a high G harmonic, or play the same note by pressing the string down to the fingerboard.
Divide the String in 3rds
Look at the bass and estimate the string divided in 3rds. At these points, you'll find another harmonic. This harmonic, on the G string for example, is an octave-and-a-fifth above the open string--a very high D.
Divide the String in Quarters
If I play the high D harmonic on the G string with my 4th finger (by dividing the string in 3rds), I find that under my first finger, there's another harmonic. This harmonic is two octaves above the open G string. You might notice that this length of string--from my first finger to the nut--divides the string into quarters. You can find harmonics up and down each string on the bass, and they are extremely useful for keeping your orientation and intonation in check.