Unit 5 · Lesson 5 of 12 — IB MYP: Personal and Cultural Expression · Communication
Building Triads
A basic triad stacks three notes using alternating scale tones.
In this lesson
Learning Targets
Each section below is labeled with the target it teaches. The questions and your Noteflight task practice every target.
Target 1Build a triad by stacking scale degrees 1–3–5 from a starting scale degree
IB MYP connection
Command terms: CONSTRUCT
Construct
Learner Profile · ATL
Knowledgeable · Thinker — Thinking: connect scale and chord knowledge to the melodies and harmonies you build.
Task
Use what you're learning to notice this in the music you already know, and be ready to apply it in your next Noteflight task.
Inquiry: Why does the same 1–3–5 method work no matter which scale degree you start building from?
Reflect: What did “Building Triads” teach you about your own composing choices?
Key words
Words you will use today
Chord
Three or more pitches sounding at the same time.
Triad
A three-note chord built from the scale by stacking every other note: a starting note, the note a 3rd above it, and the note a 5th above it.
Root, 3rd, 5th
The root is the note a triad is built on and named for. The 3rd and 5th are the notes a 3rd and a 5th above the root. The G triad is G (root), B (3rd), D (5th).
From scale to chord
Target 1
Stack every other note of the scale
A triad is built from the scale. Choose a starting note, the root. Skip the next scale note and take the one after it (a 3rd above the root), then skip again and take the next (a 5th above the root). Counting from the root as 1, that is scale notes 1–3–5. On the staff, a triad built this way sits on three neighboring lines or three neighboring spaces. In this lesson every triad has its root on the bottom; Building chords, next, measures triads in half steps, and Chords: Part 2 restacks the same three notes in other orders.
01
From the scale to the triad
In C major, start on C and take every other note: C (skip D) E (skip F) G. Played together, C–E–G is the triad built on C.
The scale, with every other note from C in orange, then the triad C–E–G.02
Root, 3rd, and 5th
The triad on G in G major is G–B–D. G is the root, and the triad is named for it: the G triad. B is its 3rd and D is its 5th, the intervals you counted in Unit 1.
The G triad in G major, one note at a time and then together.03
Any degree, same method
A triad can start on any scale degree. The key signature still applies: in G major, the triad built on degree 5, D, is D–F♯–A, because every F in G major is F♯.
The triad on D in G major: D, F♯, A. The key signature supplies the F♯.
Worked analysis
Target 1
Building three triads from one scale
The 1–3–5 method works from any root, not only the three you will meet by name in the next lesson. Here it is applied to three different starting notes in the same key, to confirm the method itself before narrowing in on three special cases.
An original example, not from a real piece: three triads in G major, each built the same way — starting note, skip one, skip one again.
Root
Method
Triad
B
B (skip C) D (skip E) F♯
B–D–F♯
E
E (skip F♯) G (skip A) B
E–G–B
A
A (skip B) C (skip D) E
A–C–E
Model description: Each triad uses the identical method: name the root, skip the next scale note, take the one after it, skip again, take the next. The only thing that changes from one triad to the next is the starting note; the key signature supplies any sharps automatically, so the pattern of skips is always every other scale note, never a fixed number of letter names.
Notice the method: count 1–3–5 from the root every time, regardless of which scale degree you start on. This works for all seven possible roots in a key, not just three of them — Primary Chords & Melody, next, narrows in on why three specific ones get special names.
Check your understanding
Try it before you compose
Pick an answer for each question. You will see right away whether you are correct and why.
0 of 4 correct
1Listen only. Which description matches what you hear?
Target 1
2Build a triad in G major starting on degree 4 (C). Which three notes are in it?
Target 1
3Listen, then choose which excerpt you heard.
Target 1
A
B
4Which group of notes is the triad built by the 1–3–5 method, starting on E, in C major?
Target 1
Take it to Noteflight
Build three triads using the 1–3–5 method
Every triad, no matter which note it starts on, is built the same way: root, skip, skip. Practice the method itself before the next lesson narrows in on three special triads.
Your Noteflight task
In C, G, or F major (with the key signature), choose three different scale degrees to start on (not the same note twice) and write each as a whole-note triad on the treble staff, root on the bottom. Label each triad by its root letter name. Play each one.