Bass Fretboard Symmetry

Welcome to Bass Fretography.

Though the bassist is not faced with the complexities of the layout of the guitar fretboard – since all the strings of the bass are tuned to the same interval, and bassists are less likely to play chords – a clear picture of all the note positions on the fret board is essential if you're going to master the instrument.

The Fretography method, originally created for guitar, has clear advantages for bass as well. Starting with this post, this blog will present a series of tutorials to help you become totally adept at navigating the fret board.

The four strings of the bass are tuned E A D G; a series of 4ths from low to high. Because the intervals are all the same, the note positions on the bass fret board contains some interesting symmetries.

Let's look at the notes of the key of C on the bass fret board;

The symmetries are not immediately apparent. But when certain important landmarks are highlighted, the note patterns become more structured;

The gray ovals above are connecting the half-step positions in the key of C. Another set of landmark positions is the axis frets – fret positions on which the notes of the key align;

Notice that there is an axis on the open strings, the 5th fret, 7th, 10th, 12th and 17th frets in the diagram. (Of course, the 12 fret is the same set of notes as the open strings, so the 17th is the same as the 5th fret, the 19th would be the same as the 7th, and – if your bass has a long enough neck, the 22nd and 24th frets are repeats of the 10th and 12th frets.) 

Now let's combine the axis positions and the half-step clusters;

Notice that the 6th, 11th and 18th fret have no notes in the key of C. 

If we group all the fret positions which have notes belonging to the key, we have two basic zone forms;

Notice that the zone which spans the open string position to the 5th fret is the same structure as the one spanning the 12th to 17th fret. The smaller zone running from the 7th to 10th fret would also repeat from the 19th to 22nd fret.

Below you see the zones with the half-step clusters and the axis frets highlighted;

These two zones comprise all the notes of every key on the fretboard, the patterns are the same whether you are playing in the key of C, D, E, Bb, Eb etc. ... they are simply shifted to different fret positions.

It will be easier to explore all the possibilities of using these zone patterns if we give them names. So we'll use the lowest note in each zone as the basis for naming them. But rather than using the alphabetical note names, which will will change when we shift to different keys, we'll use the mode which begins at those note positions.

E is the 3rd step of the key of C, and is the note on which the Phrygian mode is based. The Phrygian mode is the 3rd mode of every major key. The zone which is based on the open position in the key of C will still be based on the 3rd step of whatever key you play in ... that is the Phrygian zone;

... and the zone based on B in the key of C is called the Locrian zone because the Locrian mode is the 7th mode, just as B is the 7th note of the key;

If you learn these two patterns you will know where all the notes on the fretboard are;

Let's replace the note names with Roman numerals, which indicate the scale degree of each note;

This is what happens when we move to the key of F;

Notice that the two zones have shifted their overall position on the fret board, but the scale degrees within them remain the same. Below you see the note names in the key of F;

If you play all the notes within each zone in sequence from low to high and back again, naming the scale degrees as you play, you'll have a real picture of the shape of every key.