Major scale across the fretboard

Playing a scale on one string works, but it requires shifting your hand a lot. The standard way to play scales on bass uses a "box pattern" across multiple strings. Less shifting, more notes.

The two-octave C major box

Starting on the A string at the 3rd fret (C), the pattern goes:

Start with your middle finger on A string fret 3:

1. A string, fret 3 (C, root), middle finger
2. A string, fret 5 (D), pinky
3. D string, fret 2 (E), index
4. D string, fret 3 (F), middle
5. D string, fret 5 (G), pinky
6. G string, fret 2 (A), index
7. G string, fret 4 (B), ring
8. G string, fret 5 (C, octave), pinky

That's one octave. To continue up to the second octave:

1. G string, fret 7 (D), index (shift up)
2. G string, fret 9 (E), shift, pinky
3. G string, fret 10 (F), index of new position
4. G string, fret 12 (G), ring
5. G string, fret 14 (A), pinky (or shift, depending on the bass)
6. G string, fret 16 (B)
7. G string, fret 17 (C)

70 BPM. One note per beat. Up the scale, down the scale. Loop.

The whole point: this box moves

The box pattern at the 3rd fret = C major. The same box pattern at the 5th fret = D major. At the 7th fret = E major. Each fret up shifts the entire scale up a half step.

This is the #1 most important concept in bass: scales are shapes, not specific notes. Learn the shape once. Move it. You know every major scale.

Next: locking root notes to chord changes.