THIRDS ON BASS
A very useful pattern to learn on the bass are third patterns. A third is a tone on the third degree from a given tone. Or, put simply, the third number in our major scale number system. A flat third is one semitone (one fret) below that.
Now that you’ve learned your thirds, you can build arpeggios or chord shapes into your playing. You can build your arpeggios by combining your thirds and fifths together. Major chords/arpeggios follow the formula 1 3 5, and minor chords/arpeggios follow the formula 1 b3 5. The diagram below shows the major and minor shape arpeggios you need to know.