Think of a scale as a note pool: a set of notes that will usually sound “in key.” For a bass player, that pool is where you pull notes for grooves, fills, and connecting lines. The key idea is simple: chord tones first (the notes that define the harmony), and scale tones as decoration (passing notes, approach notes, and fills).
1) Major scale pattern (whole/half steps)
The major scale is defined by a fixed step pattern:
Whole Whole Half Whole Whole Whole Half
W W H W W W HOn bass, “whole step” = 2 frets, “half step” = 1 fret. If you start on any note and follow that W-W-H-W-W-W-H pattern, you get the major scale for that starting note (your key center).
One movable fingering shape (2-octave-friendly idea)
Here is a common movable major scale shape that works well for bass lines because it stays compact. Start with your index finger on the root (degree 1). The example below shows the degree numbers you’ll play; move the whole shape to any root to change keys.
Major scale (movable) — degree map
G string: 2 3
D string: 6 7 1
A string: 3 4 5
E string:1 2
(“1” is the root note you choose. Keep the same pattern; slide it to a new root.)Practice tip: don’t rush. Play the shape slowly, say the degrees out loud (1-2-3-4-5-6-7-1), then play it again naming the note names in a specific key.
- Listen to the audio with the screen off.
- Earn a certificate upon completion.
- Over 5000 courses for you to explore!
Download the app
2) Naming degrees (1–7) so you can target sounds
Inside a major key, each note has a scale degree number. Degrees help you think in functions (what the note does) rather than only letter names (what the note is).
| Degree | Name (common) | Practical bass use |
|---|---|---|
| 1 | Tonic | Home base; strongest landing note |
| 2 | Supertonic | Common passing/approach note |
| 3 | Mediant | Defines major/minor quality with chord tones |
| 4 | Subdominant | Leads toward 5; good for motion |
| 5 | Dominant | Strong support note; drives back to 1 |
| 6 | Submediant | Great “sweet” chord tone in vi; common in pop |
| 7 | Leading tone | Strong pull up to 1; use carefully in bass |
When you’re building bass lines, you’ll often feel that 1, 3, 5 sound stable (they outline the chord), while 2, 4, 6, 7 often sound like motion or color depending on the chord underneath.
3) Building diatonic triads from the scale (example: G major)
“Diatonic” means “from the key.” If you stay inside the major scale note pool and stack notes in thirds (every other scale degree), you get the set of chords that naturally belong to that key.
Step 1: Write the G major scale
G major uses the notes:
G major scale degrees:
1 2 3 4 5 6 7
G A B C D E F#Step 2: Build triads by stacking 1–3–5 from each degree
To build a triad on a degree, take that degree as the root, then add the note a third above (skip one scale note), then the fifth above (skip one more). In degrees, that’s always:
Triad formula inside the key: 1–3–5 (relative to the chord’s root)But in the key, it looks like “every other degree”:
- I chord uses degrees 1–3–5
- ii chord uses degrees 2–4–6
- iii chord uses degrees 3–5–7
- IV chord uses degrees 4–6–1
- V chord uses degrees 5–7–2
- vi chord uses degrees 6–1–3
- vii° chord uses degrees 7–2–4
Step 3: See the actual chords in G major
| Chord (Roman numeral) | Built from degrees | Notes in G major | Triad quality |
|---|---|---|---|
| I | 1–3–5 | G–B–D | Major |
| ii | 2–4–6 | A–C–E | Minor |
| iii | 3–5–7 | B–D–F# | Minor |
| IV | 4–6–1 | C–E–G | Major |
| V | 5–7–2 | D–F#–A | Major |
| vi | 6–1–3 | E–G–B | Minor |
| vii° | 7–2–4 | F#–A–C | Diminished |
Practical takeaway: the scale isn’t just a run to memorize. It’s a map that tells you which chords belong to the key and which notes are the most stable targets when those chords happen.
4) Quick play-along: build a bass line using mostly degrees 1, 3, 5, and 6
In many beginner-friendly grooves, you can sound solid by leaning on 1, 3, 5 (chord-defining tones) and adding 6 as a very common “in-key” color tone (often a chord tone when the harmony is vi, and a smooth melodic option in major keys).
Step-by-step recipe (in G major)
- Choose a simple progression that stays diatonic. Use:
| G | Em | C | D |(I–vi–IV–V in G major). - For each chord, identify the chord tones from the table above:
- G: G–B–D (degrees 1–3–5)
- Em: E–G–B (degrees 6–1–3)
- C: C–E–G (degrees 4–6–1)
- D: D–F#–A (degrees 5–7–2)
- Write a 1-bar pattern per chord using mostly chord tones. Aim for roots on beat 1, then add 3rd/5th (or 6 where it fits).
- Add decoration last: if you want motion, use other scale degrees as quick passing notes between chord tones, but land on chord tones on strong beats.
Example bass line (8th-notes, 4/4) staying mostly on 1, 3, 5, 6
This line targets chord tones on beats 1 and 3, and uses mostly degrees 1, 3, 5, 6 across the progression.
Progression: | G | Em | C | D |
Notes: | G B D B | E G B G | C E G E | D A F# A |
Degrees: | 1 3 5 3 | 6 1 3 1 | 4 6 1 6 | 5 2 7 2 |Notice what’s happening:
- On G, you’re outlining 1–3–5 clearly.
- On Em, degree 6 becomes the root (E), so your “favorite degrees” still work because they’re chord tones here (6–1–3).
- On C, degree 6 (E) is a chord tone, so it still feels stable.
- On D, the line uses chord tones too, but you can hear that degrees 2 and 7 are more “active” than 1/3/5/6—good to use, but best when you resolve cleanly.
Make it your own (still “chord tones first”)
Try these controlled variations while staying in the G major note pool:
- Swap the order of chord tones: on G, try
G D B Dinstead ofG B D B. - Add one passing note between two chord tones (decoration): on G, between G and B, try
G A B(degrees 1–2–3) as 8th-notes, but still land on B or D on strong beats. - Use degree 6 as a melodic hook: in G major, E (degree 6) can be a repeating “signature” note, but check that you’re not sitting on it when the chord makes it clash—use it as a move toward a chord tone.
When in doubt: place the root on beat 1, aim for another chord tone on beat 3, and treat the rest of the scale as optional motion that must resolve back to stability.
