The major scale is the foundation of Western music. Every other scale (minor, blues, modal, pentatonic) is a modification of it. You'll start by playing it on a single string, which makes the spacing obvious.
The interval pattern
A major scale is built from intervals: W-W-H-W-W-W-H (whole step, whole step, half step, etc.). On a bass:
- Whole step = 2 frets
- Half step = 1 fret
C major on the A string
Start on the A string, 3rd fret (that's the note C). Play these frets in order:
A string: 3 - 5 - 7 - 8 - 10 - 12 - 14 - 15
note: C - D - E - F - G - A - B - C
interval: R W W H W W W H
The visualizer shows every C major note on the bass fretboard. The notes you just played are all on the A string.
70 BPM. One note per beat. Play the whole scale up, then down. Loop for five minutes.
Why one string first
Played on one string, the pattern of whole-and-half-steps is visible: gaps of 2 frets, gaps of 1 fret. Once you see that pattern, you can play the major scale starting on any fret of any string. The pattern travels with you.
Next: the major scale across multiple strings. The standard "box pattern" used in 99% of bass playing.