If you are comfortable with the relationship between scales, arpeggios, triads and chords, you can create bass lines with ease as well as strengthen your musical ear. This video takes you through the formation of major, minor, diminished and augmented triads.
Briefly, triads are formed from the first, third and fifth notes of a scale. They are built by stacking thirds. A 'third' is an interval - the distance between two musical pitches. There are two types of third: a minor third and a major third and there are only four possible combinations:
- Major Third + Minor Third = MAJOR TRIAD
- Minor Third + Major Third = MINOR TRIAD
- Minor Third + Minor Third = DIMINISHED TRIAD
- Major Third + Major Third = AUGMENTED TRIAD
It is a very good idea to learn two patterns (at least) on the bass so you have freedom to move in any direction on the fretboard.
Memorise those shapes inside out and then practise them over the following chord changes. Watch the video for a demo of this.
The idea behind every lesson on this site is to provide a musical context to a subject and it is important to make music immediately when learning music theory. Always aim to associate anything you learn on the bass to an actual musical idea -. that's what we picked up the bass to do: make music!
If you haven't watched the scale video, I recommend doing that. Here's an infographic that outlines the relationship between scales, triads, arpeggios and chords.