Capstone: Analyzing and Composing a Short Original Piece

Music Theory Fundamentals

Chapter 10 (Capstone) · Analyzing and Composing a Short Original Piece

No new theory in this chapter — just every real tool from Chapters 1 through 9, applied in sequence to write and fully analyze one short, original 8-bar melody from scratch.

Step 1 — Key and Time Signature

This piece is written in C major (Chapter 3 — no sharps or flats) in 4/4 time (Chapter 6 — a quarter note gets the beat, four beats per measure). C major is picked deliberately as this course's own reference key from Chapter 1 onward.

Step 2 — The Antecedent Phrase (Bars 1–4)

The opening four-bar phrase — the antecedent — states the main melodic idea and ends on a real, deliberately unresolved cadence:

Bars 1-4, melody and harmony

Melody: C4–E4–G4–E4 | F4–A4–G4–(rest) | E4–D4–C4–D4 | E4–(half note)
Harmony: C (I) | F (IV) | G (V) | G (V)
The melody moves by a real major 3rd (C to E, Chapter 4) to open, then a real perfect 4th (E to A, Chapter 4) in bar 2. The phrase ends on the V chord (G major) — a real half cadence (Chapter 8), leaving the ear genuinely wanting more.

Step 3 — The Consequent Phrase (Bars 5–8)

The second four-bar phrase — the consequent — echoes the antecedent's own opening melodic shape, then resolves fully:

Bars 5-8, melody and harmony

Melody: C4–E4–G4–E4 | F4–A4–B4–(rest) | C5–B4–A4–G4 | C4–(whole note)
Harmony: C (I) | F (IV) | G (V) | C (I)
Bars 5-6 real, deliberately mirror bars 1-2 — this is what makes the two phrases a genuine, matched pair rather than two unrelated ideas. The final bar resolves V to I with both chords in root position and the tonic on top — a real, textbook perfect authentic cadence (Chapter 8), giving the piece its own genuine sense of closure.

Step 4 — The Full Harmonic Analysis

Every chord in this piece is built directly from Chapter 5's own triad-construction rules, applied to the C major diatonic set Chapter 7 already derived:

Bar	Chord	Roman numeral	Notes
1, 5	C major	I	C-E-G
2, 6	F major	IV	F-A-C
3, 7	G major	V	G-B-D
4	G major	V	Half cadence
8	C major	I	Perfect authentic cadence

The whole eight-bar harmonic plan is simply I-IV-V-V | I-IV-V-I — the same real I-IV-V-I progression Chapter 8 already introduced, split across two phrases with a half cadence marking the midpoint instead of a full resolution.

Step 5 — Naming the Form

Two matched four-bar phrases — an antecedent ending in a half cadence, and a consequent that echoes the antecedent's own opening before resolving fully — together form what's traditionally called a period: the smallest real complete musical structure built from a genuine question-and-answer pair of phrases. It's a real, direct miniature relative of Chapter 9's own binary form (two related sections), scaled down to the level of a single melodic idea rather than a whole movement.

Capstone element	Built using
Key & time signature	Chapter 3, Chapter 6
Notation, note values	Chapter 2
Melodic intervals (3rd, 4th)	Chapter 4
Chord construction	Chapter 5
Roman numeral analysis	Chapter 7
Half and perfect authentic cadences	Chapter 8
Period form (antecedent/consequent)	Chapter 9

Hands-On Exercises

Exercise 1

Rewrite this chapter's own consequent phrase (bars 5-8) so that it ends with a real deceptive cadence instead of a perfect authentic cadence — state which chord bar 8 would need to become, and explain your reasoning using Chapter 8's own material.

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Exercise 2

This piece's whole 8-bar harmonic plan is I-IV-V-V | I-IV-V-I. Rewrite it to use a ii-V-I progression (Chapter 8) somewhere within the consequent phrase instead of the plain IV-V-I, and name the new chord you introduced along with its Roman numeral.

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Exercise 3

Explain, in your own words, why bars 5-6 mirroring bars 1-2 is essential to calling this piece a genuine "period" rather than just two unrelated four-bar phrases placed next to each other.

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Chapter 10 (Capstone) Quick Reference

A full 8-bar piece built from every prior chapter's own real tool: key/time signature, notation, intervals, diatonic chords, Roman numerals, cadences, and form
Harmonic plan: I-IV-V-V | I-IV-V-I — a half cadence at bar 4, a perfect authentic cadence at bar 8
A period — an antecedent phrase (ending unresolved) matched with a consequent phrase (echoing the opening, then resolving fully) — is the smallest complete musical structure, a miniature relative of Chapter 9's own binary form

Course Complete

Music Theory Fundamentals is now complete — 10/10 chapters, from the physics of a single vibrating string all the way to a fully analyzed original composition.