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Week 13 · Lecture outline

Week 13 — Lecture Outline · Progression, and Two Independent Voices

Music Theory I · MUS 156 Fictional sample

Course: MUS 156 Music Theory I · Kenosis College
Instructor: Professor Hemsworth
Unit: Learning Unit 13 of 16 (Week 13) · two sessions per week
Objectives: SLO 6 (write and analyze two independent voices observing voice-leading norms) · SLO 7 (translate what you hear into names and notation — the spine)
Sessions: session 1 — teach · session 2 — studio

You already hear this. We're going to name what you already know.

Sung in Aural Skills I: rounds in two groups — Frère Jacques and Row, Row, Row Your Boat split across the room; MUS-155 sings the two-voice independence you'll name here this morning, so the parallel-fifths hunt your pencil ran in this class gets heard from inside the texture in Aural Skills I.

Week at a Glance

The table below summarizes the unit in one screen.
The unit's big question "You've sung a round and felt two melodies hold their own shape at once. What keeps two lines independent — and what quietly fuses them back into one?"
By the end of the unit, students can… (1) run the functional cycle as a working norm — tonic anywhere, predominant to dominant, dominant home (or the deceptive detour); (2) label the four motion types between two voices: contrary, oblique, similar, parallel; (3) spot and avoid parallel perfect fifths, octaves, and unisons — and say honestly why (independence, not ugliness); (4) tell a direct (hidden) fifth or octave from a parallel one; (5) keep voices out of each other's lanes — no crossing, no overlap, ranges respected; (6) resolve tendency tones — the leading tone rises to do, the chordal seventh falls by step; (7) write a second voice against a given line that passes the course's voice-leading check.
Key vocabulary contrary motion, oblique motion, similar motion, parallel motion, parallel fifths, parallel octaves, direct (hidden) fifth/octave, voice crossing, voice overlap, range, tendency tone, leading tone resolution, chordal seventh resolution, second voice, round
Materials Deck 13 · the Week 13 chapter · a piano or keyboard in the room · studio writing sheets (the second session) · students' own instruments and voices welcome the second session — the rounds want them
Timing note 7 segments ≈ 150 min. Session 1 = Segments 1–6 (75). Session 2 = Segment 7 (75: studio). Scale to your own pacing.

Segment 1 — Ear first: sing the round (9 min) · Session 1 opens

Hook (no notation on screen yet). Split the room in half and sing Frère Jacques as a round — group two enters when group one reaches "Dormez-vous?" No handout, no staff, no explanation. It will work on the first try, because everyone in the room has been singing rounds since childhood.

  • Then ask the only question that matters: "You just sang two different melodies at the same time and never lost your own. How? Nobody was reading. What kept the two lines apart?"
  • Collect answers — they'll be good ones: "we were doing different rhythms," "when they moved, we were holding," "we were higher, they were lower." Every one of those is a voice-leading principle wearing street clothes.
  • The promise (say it, then put it on the board): "By the end of this week you can write the second line yourself — a harmony vocal, a countermelody, a bass line that stands on its own — and prove it holds up, using the same checker this course uses."
  • Say the spine out loud: the round worked because your ear already knows what independence sounds like. This week names the machinery.

Memory hook: "Two lines are independent when each one would survive alone."

Segment 2 — The engine, in practice: progression norms (10 min)

Plain language first. Unit 11 named the functional cycle — T → PD → D → T — and unit 12 named its landings. Before we add a second voice, one working recap of how diatonic progressions actually behave, because the second voice lives on top of that engine.

  • Tonic can go anywhere. I (and its family, vi and iii) opens doors: to a predominant, straight to a dominant, wherever the song needs.
  • Predominant leans forward. ii and IV pack the bags: their normal next stop is the dominant — V or viio.
  • Dominant goes home. V (or V7) resolves to I — or takes unit 12's deceptive detour to vi, which just delays the same promise.
  • Play a lap in C at the piano while naming it: I – IV – V7 – I, then I – vi – ii – V7 – I. The room has heard ten thousand of these; the point is that the wheel turns one way in the norm — the map they'll harmonize in the studio.

Misconception + cure:

  • ❌ "Progression norms are laws — V can never move to IV."
    ✅ Cure: they're norms, not laws — the statistical gravity of the style, and the reason your ear can predict a chart it's never seen. Real songs bend them on purpose (half the rock canon runs V–IV–I). The norm is the rope you deviate from; this week we practice the rope.

Segment 3 — Two lines, four relationships (14 min)

Ear first. Play two voices at the piano moving apart, then together, then in lockstep. Ask "same or different behavior?" before naming anything. The room can sort the behaviors by ear; then attach the four names. Any moment of two-voice music is one of these:

  • Contrary motion — the voices move in opposite directions. The strongest independence there is.
  • Oblique motion — one voice holds while the other moves. The round ran on this.
  • Similar motion — both move the same direction by different distances. Fine, with one caution coming in Segment 4.
  • Parallel motion — both move the same direction by the same interval. Legal and lovely in thirds and sixths; fatal in the intervals Segment 4 names.

Show the sound the room already trusts — the moment in the round where the two groups overlapped:

KEY: C major    METER: 4/4    CLEF: grand
U: | E4/q F4/q G4/h |
L: | C3/q D3/q E3/q C3/q |

The round's overlap moment on the grand staff: the upper voice sings "Dor-mez-vous?" — E4, F4, then G4 held — while the lower voice, an octave-down latecomer, walks its opening "Frè-re Jac-ques": C3, D3, E3, back to C3. The first three beats move in parallel tenths (C3 up to E4 is a major tenth; D3 to F4 and E3 to G4 are minor tenths); then the upper voice holds G4 while the lower voice falls to C3 — oblique motion, landing on a perfect twelfth. Two behaviors, four beats, zero collisions.

Misconception + cure:

  • ❌ "Parallel motion is banned."
    ✅ Cure: parallel thirds, sixths, and tenths are the bread and butter of every duet, harmony vocal, and country chorus alive. The ban — next segment — covers exactly three intervals. Say "parallel" and your ear should ask "parallel what?"

Segment 4 — The independence rules: parallel and direct perfects (15 min)

Ear first. Play a phrase doubled entirely in perfect fifths, loud. Ask the room to describe the sound — not judge it, describe it. The words that come back are the lesson: hollow, medieval, chant-like, "like one big weird voice." Exactly.

  • Rule 1 — no parallel perfect fifths, octaves, or unisons. When two voices move in parallel at a perfect interval, the ear stops hearing two voices. A perfect interval is so acoustically fused that the two lines snap together into one thick line. Octaves are the extreme case: doubling the tune an octave down isn't a second voice — it's the same voice in boots.

```music counterexample
KEY: C major METER: 4/4 CLEF: grand
U: | C4/q D4/q E4/q D4/q |
L: | F3/q G3/q A3/q G3/q |


A deliberately broken example (the checker flags every move): the upper voice walks C4–D4–E4–D4 while the lower voice shadows it at F3–G3–A3–G3 — a perfect fifth under every single note (F3–C4, G3–D4, A3–E4, G3–D4). Sing either line alone: fine. Together: one hollow super-voice. This is the parallel-fifths sound — the room should *hear* it before hunting it.

- **Say the honesty out loud:** parallel fifths don't sound *bad*. They sound like organum — a thousand years old and gorgeous in the right style, and alive today in every power-chord riff, which is one guitarist deliberately playing a thickened single line. The rule isn't about ugliness. **It's about independence:** this unit's whole job is two lines that survive alone, and parallel perfects quietly weld them together.
- **Rule 2 — no direct (hidden) fifths or octaves.** Both voices move the *same direction* into a perfect interval, with the upper voice **leaping**. The fifth wasn't there and suddenly is — the fusion appears out of nowhere, which is why "hidden" is the old name. Approach perfect intervals by **contrary or oblique** motion — or in similar motion with the upper voice stepping — and they're welcome.

**Misconception + cure:**

- ❌ *"Direct fifths are just parallel fifths — same thing."*
  ✅ **Cure:** parallel = fifth **to** fifth. Direct = *arriving at* a fifth (or octave) in similar motion with an upper-voice leap — no fifth before it. Different fault, different fix, and the checker names them differently. Being able to tell them apart is the studio's swap round currency.

---

## Segment 5 — Stay in your lane: crossing, overlap, range (10 min)

**Plain language first.** Independence also fails when the listener loses track of *which line is which*.

- **Voice crossing** — the lower voice sounds **above** the upper voice at the same moment. In this unit's writing, we don't: two lines the ear can't rank aren't two lines, they're a tangle. (Skilled writers cross voices on purpose for color — the honest version is that crossing isn't evil, it's *advanced*, and here, where clarity is the whole assignment, we keep each line in its lane.)
- **Voice overlap** — sneakier: nobody is above anybody *at the same moment*, but a voice moves past the note the other voice **just sang**. The ear, tracking by memory, briefly hands the melody to the wrong singer.
- **Range** — every voice and instrument has a comfortable lane. A second voice that keeps clawing at the top of somebody's range isn't independent, it's cruel. Name the lane before you write, and stay in it.

Where the room already met an overlap — the round itself, at the "do–so–do" dive:

```music counterexample
KEY: C major    METER: 4/4    CLEF: grand
U: | C4/q G3/q C4/h |
L: | G3/e A3/e G3/e F3/e E3/q C3/q |

A deliberately colliding bar from stacking the round's later phrases: the upper group's "do–so–do" tag (C4, down to G3, back to C4) lands on top of the lower group's running "so-la-so-fa-mi-do" line. When the tune dives to G3, it drops below the A3 the lower voice just sang — the checker flags an overlap, plus a leap into a unison in similar motion (a direct unison). A round is built for everyone singing the same tune, not for two engineered lines — which is exactly why we're learning to write the second line instead of borrowing it.

Misconception + cure:

  • ❌ "Voices can never cross — it's a law of music."
    ✅ Cure: it's a rule of this room, this month: two-voice writing where clarity is the assignment. Orchestrators and arrangers cross lines deliberately for color. Learn the lane discipline now; earn the license later.

Segment 6 — Tendency tones, the writing procedure, and the AI-critique moment (17 min) · Session 1 closes (~75)

Ear first. Play a V7 in C and stop on it (the room knows this game from unit 12). Ask: which notes are itching? They'll find both: the B wants up, the F wants down. Name them:

  • The leading tone rises to do. Ti is a promise; in a two-voice close, B goes to C. Leaving it hanging — or dropping it — breaks the strongest pull in the key. The leading tone is not optional.
  • The chordal seventh falls by step. The F in G7 is the chord's seventh; it resolves down to E. Sevenths fall. That's the whole rule, and your ear has enforced it for years.
KEY: C major    METER: 4/4    CLEF: grand
U: | B3/h C4/h | F4/h E4/h |
L: | G2/h C3/h | G2/h C3/h |

Two tendency resolutions over a sol–do bass, on the grand staff. Bar one: the upper voice sings ti rising to do — B3 to C4 — over a bass climbing sol to do, G2 to C3: a major tenth opening onto an octave. Bar two: the upper voice takes the seventh of the dominant — F4 — and lets it fall by step to E4 over the same sol–do bass: a minor fourteenth resolving to a major tenth. Both bars pass the checker clean; both are the sound of a close done right.

Then the procedure — writing a second voice against a given line (the week's deliverable, and the studio):

  1. Know the engine. Read the tune's implied progression (Segment 2) — your line should agree with it.
  2. Default to imperfect. Thirds, sixths, tenths are the workhorse intervals — they harmonize without fusing.
  3. Spend perfects at arrivals. Octaves and fifths mark beginnings and cadences — approach them by contrary or oblique motion.
  4. Vary the motion. If the tune steps up, consider stepping down; if it leaps, hold. Contrary and oblique are independence on tap.
  5. Honor the tendencies. If either line has ti or a chordal seventh, its next note is already decided.
  6. Run the two-rules pass. Consecutive perfect pairs in similar motion? Any moment the lower line is above the upper? Fix before anyone hears it.

AI-critique moment (3 min, live on the projector). Paste into a chatbot: "In two-voice writing: upper voice C4 then D4, lower voice F3 then G3. Any voice-leading problem? One sentence." Read the answer aloud. Tools regularly miss the parallel fifths sitting in plain sight (F3–C4 to G3–D4), miscount the interval, or — the mirror failure — condemn perfectly legal parallel thirds as "parallel motion errors." Have the room check it by hand: letter distance, then quality. "All term the tool drafts and you judge — and this week your judgment gets backed by the course's own checker in the studio."

Why this makes you a better musician

This is the week your arrangements stop being karaoke. The harmony vocal you improvise on Sunday morning — the one that keeps accidentally melting into the melody — melts because it's riding parallel perfects; now you know to slide it to thirds and sixths and spend the octave on the last note, approached from the other direction. The bass player who asks "roots again?" can be handed a line with a shape of its own — contrary motion under the tune's climb, a held note under its run — and it will sound arranged instead of doubled, because it is. And when a bandmate's countermelody feels muddy, you can say exactly why in ten words: "you're crossing above the lead in bar two — drop it a third." In the studio you'll write the line, swap sheets, hunt each other's parallels, and check the verdicts against the same software gate this course's own materials had to pass. Two lines, both alive: that's the skill.

Callback + tease + hand-off.

  • Callback: "The round you sang at 8:02 already contained every rule we named today — oblique motion, spent perfects, lanes kept. Your ear ran the checker before you knew there was one."
  • Tease: "Next unit — Melody and non-chord tones: your two clean lines learn to decorate. The notes between the chords — the leans, the fills, the ones your favorite singer bends — get names."
  • Hand-off: read the chapter if you haven't; Tutorial 13 with your AI tutor is due before Week 13's second session — the studio's writing and hunting assume its reps. Practice set, quiz, discussion, and The Second Voice assignment (which carries Chart milestone 3: lead sheet drafted) close the end of Week 13. Bring your Chart song's progression draft to the week — the milestone turns it into a page another musician could play from.

Segment 7 — Studio: "Round to two voices" (75 min) · Session 2

Run from the studio sheet (P-studio-week-13). Shape, for planning: sing the rounds in two groups (ears first, every time) → map why the round works on the printed overlap moments (motion types + harmonic intervals) → the parallel hunt on four printed passages, verdicts checked against the course's voice-leading checker → each table writes a second voice against a given line → tables swap sheets and hunt each other's parallels, with Professor Hemsworth spot-running the checker live. The studio is the payoff enacted: hear the independence, name it, then build it. 20 points, graded in session; async make-up path (full credit) on the studio sheet.

Instructor FAQ — common stumbles

The table below lists predictable Week 13 questions and quick cures.

Student says / does Quick cure
"Parallel fifths sound fine to me — power chords are my whole life." Agree — enthusiastically. Power chords are a style built on the fused sound: one guitarist playing one thickened line. The rule here serves a different job: two lines that each survive alone. Same physics, different goal. Never argue "ugly"; argue "fused."
Flags parallel thirds as an error in the hunt. "Parallel what?" is the reflex to install. The ban covers perfect intervals only — fifths, octaves, unisons. Thirds and sixths in parallel are the sound of every duet they love.
Calls every fifth a parallel fifth. One fifth is an interval; two in a row in the same voices, moving together, are parallels. A single P5 at a cadence, approached by contrary motion, is textbook-correct.
"Direct fifth, parallel fifth — same thing, right?" Parallel: P5 → P5. Direct: some other interval → P5, similar motion, upper voice leaping. The checker literally prints different words for them; make students quote it.
Writes the second voice by doubling the tune a sixth below, wall to wall. Legal — and limp. Push for one moment of contrary motion and one held note per phrase. "Would your line survive alone?" is the test; a shadow wouldn't.
"Why can't my lower voice pop above the melody for one pretty note?" In this unit, clarity is the assignment: the listener must always know which line is the lead. Crossing is real-world advanced technique — earned later, avoided here.
Lets the leading tone droop (B down to G in a C major close). Play their version, then ti–do, back to back. The room's wince does the teaching. The leading tone is a promise; this course keeps it: ti rises to do, every time.
Forgets the seventh falls (F in G7 wandering up). "Sevenths fall." Three syllables? Say it, sing F–E over G–C, move on. The full poetry of why arrives with next unit's dissonance work.
"My round broke the rules and it still sounded great." Correct — a round is the same tune stacked on itself, built for unison singers, not engineered lines. It's the ear-opener, not the model. The model is the line they write in the studio, which must pass the checker.

Scope flag

This outline stays inside Week 13's fourteen ledger concepts (progression norms; contrary/oblique/similar/parallel motion; parallel fifths and octaves; direct fifths and octaves; voice crossing; voice overlap; range; two-voice writing; tendency-tone resolution; the round as two-voice independence), building on Week 6–Week 7's intervals, Week 9–Week 11's chords and Roman numerals, and Week 12's cadences. Two-voice work is framed throughout as a harmony vocal, a countermelody, or a bass line that stands on its own. Counterpoint proper — the full discipline these skills come from — waits for MUS 158, and that is the one cross-course forward-reference this unit makes. Embellishing tones and suspension figures belong to Week 14 and are not named here.

~ Professor Hemsworth's edition · Kenosis College · built with thecoursemaker.com