← Semester courseWeek 10 · Harmony

Triads and seventh chords

How does stacked-third construction connect chord spelling, sound, and function?

3 class meetings150–180 minutesGrades 8–12 adaptablePrint: use browser print

Teacher orientation

This week asks: How does stacked-third construction connect chord spelling, sound, and function? The three meetings move from shared experience to explicit theory and then transfer. Require students to predict before measuring or labeling; use performance and explanation together as evidence.

Misconceptions to anticipate

Lowest note is always root; enharmonic spellings never affect chord identity; inversion changes chord quality.

Three-meeting sequence

Meeting 1 of 3 · 50–60 minutes

Stacking thirds

Learning target

Build and spell four triad qualities

Launch · 5 min

Reorder C–E–G in several registers and ask what identity persists.

Teach · 12 min

Build root-position triads with alternating letter names; derive major, minor, diminished, and augmented qualities.

Practice · 25 min

Chord clinic: spell, play, and diagnose intentionally misspelled triads.

Exit · 5 min

Why is C–D♯–G not a correctly spelled C minor triad?

Assignment

Construct twelve assigned triads.

Meeting 2 of 3 · 50–60 minutes

Bass and inversion

Learning target

Identify root and inversion

Launch · 5 min

Place each member of a triad in the bass while retaining upper notes.

Teach · 12 min

Distinguish root from bass; teach root position, first inversion, second inversion, and figured-bass symbols.

Practice · 25 min

Students reduce keyboard textures, identify bass, reorder to stacked thirds, and label.

Exit · 5 min

Label E–G–C and explain.

Assignment

Analyze inversions in a short chorale excerpt.

Meeting 3 of 3 · 50–60 minutes

Adding the seventh

Learning target

Construct common seventh chords

Launch · 5 min

Compare triad and seventh-chord tension over the same root.

Teach · 12 min

Construct major-major, major-minor, minor-minor, half-diminished, and diminished seventh qualities.

Practice · 25 min

Ensemble arpeggiation makes each chord member audible; teams identify altered members by ear and score.

Exit · 5 min

Which seventh chord occurs naturally on V in major?

Assignment

Write diatonic seventh chords in one major key.

Student synthesis task

Claim–evidence–application: Students submit one notated or analytical artifact from the week, a 150–250 word explanation using at least four vocabulary terms, and a brief performance, recording, or demonstration. The explanation must identify a decision, cite musical evidence, and connect the idea to unfamiliar material.

Assessment and answer guidance

PromptValue
1. How do you find a chord root in close position?2 points
2. What triad is minor third plus major third?3 points
3. What is the inversion of a triad with its fifth in the bass?3 points
4. Apply the week’s central idea to a new four-to-eight-measure example and explain the reasoning.7 points
Teacher answer guidance

1. Reorder pitches into stacked thirds; the bottom of that stack is the root.

2. Minor.

3. Second inversion.

4. Award 2 points for accurate identification or construction, 2 for correct notation/terminology, 2 for evidence tied to the example, and 1 for a clear conclusion. Accept alternate solutions when the musical reasoning is defensible.

Access, differentiation, and extension

Support without lowering the target

Color root, third, fifth, and seventh consistently. Preteach vocabulary, model one complete think-aloud, reduce the number of simultaneous variables, and allow a second attempt after feedback.

Extension

Analyze incomplete chords and doublings in four-part textures.

Evidence to retain

Keep the exit tickets, synthesis artifact, and scored application prompt. Together they show factual fluency, transfer, and the student’s ability to explain music—not only select an answer.