A Procedure for Connecting Chords

The previous lesson covered the prohibitions. The trap at this point is to proceed by writing first and then searching for violations.

That is not only inefficient; it tends to go in circles, because each repair creates a new violation somewhere else. This lesson establishes a procedure under which violations rarely arise in the first place.

The order of decisions

Four-part writing proceeds in this order.

1. Bass — fixes the chord and its inversion. The foundation
2. Soprano — the most audible voice. Written as a melody
3. Inner voices (alto and tenor) — fill in what remains

There is a reason for the order. Bass and soprano are the outer voices and reach a listener most directly, so fixing them first settles the musical shape. The inner voices have narrow freedom, and leaving them until last avoids fighting for room.

Starting from the inner voices means throwing everything away the moment you want to change the bass or the soprano.

Two cases when filling the inner voices

With the outer voices fixed, fill the middle. The decision splits according to whether a common tone exists, as established in the previous unit.

With a common tone — hold it

If a note is shared with the previous chord, keep it in the same voice. That gives you a voice that does not move, and a stationary voice cannot participate in a parallel.

With no common tone — move contrary to the bass

Root motion by a second has no common tone. Here, move the upper three voices opposite to the bass.

Bass rises, upper voices fall; bass falls, upper voices rise. This guarantees that the intervals between voices change, so parallels become impossible in principle.

These two cases alone prevent the great majority of parallels. Getting the procedure into your hands is more practical than memorizing the prohibitions.

Check

Moving from ii (D–F–A) to V (G–B–D) in C major, which note is the common tone?

FADThere is none

Check answer

Voice motion has an order of preference

When filling inner voices, some kinds of motion are preferable to others.

1. no motion (holding a common tone) — most preferable
2. motion by step — next best
3. motion by a third — acceptable
4. anything larger — avoid where possible

Inner voices sit where a listener cannot easily follow them as melody, so conspicuous motion achieves nothing while making the part harder to sing. The principle is move the inner voices as little as possible.

The soprano is different. It is the melody, so a degree of leaping is welcome — but there is a convention about what follows. After a large leap, move back by step in the opposite direction.

Leaping repeatedly in one direction skews the center of gravity of the line and makes it hard to pitch. Leap, then recover. That shape keeps a melody stable.

The bass is the exception: octave leaps are freely available. The bass functions as the foundation of the harmony rather than as a melody, so jumping to the same note in another octave does not damage a melodic line.

Check

When moving the inner voices (alto and tenor), which is most preferable?

Always move by stepMatch the motion of the bassLeap as far as possibleDo not move at all if there is a common tone

Check answer

A standard formula — V7 to I

The connection you write most often has a fixed shape: V7 → I.

Two notes have predetermined destinations.

• the leading tone rises — a half step to the tonic
• the seventh falls — a step down to the third

Those two form the tritone, so they resolve by expanding outward. In C major, B rises to C and F falls to E.

Look closely at the I in Fig. 3 and the fifth, G, is missing. There are only three notes: C, C, and E.

That is not carelessness but a necessity. All four notes of V7 have assigned destinations, and moving them all as required leaves the fifth with nowhere to go. The rule from the earlier lesson — that the only note which may be omitted is the fifth — is what makes this possible.

Hearing V7 resolve

▶V7 alone▶V7 → I (correct)▶V7 → I (seventh rising)

Check: The first sounds V7 alone, with the tritone B–F audibly under tension. The second resolves it to I, and the two tense notes open outward and settle. The third deliberately sends the seventh F upward instead. The chord is still I, but listen for the snag left behind at the very point where things should have resolved.

B and F under tension

A standard formula — V to vi

The other formula is the deceptive cadence, V → vi, and it carries an exception.

The leading tone rises to the tonic. The bass rises a step from the root of V to the root of vi. Those two move in the same direction, so the remaining voices must descend in contrary motion.

The result is that the third of vi is doubled. Where the root is normally doubled, the deceptive cadence doubles the third instead.

It is a case of a rule having an exception, and the exception having a reason. Rather than memorizing it, trace why it happens and you can derive it every time.

Writing one all the way through

Applying the procedure to I – IV – V – I.

1. Bass first. All root position gives C3 – F2 – G2 – C3
2. Soprano next, keeping leaps small: E4 – F4 – D4 – E4
3. Inner voices last. I→IV holds the common tone C; IV→V has none, so move contrary to the bass; V→I holds the common tone G

The finished four-part texture

▶I – IV – V – I

Check: You can hear four voices tracing four separate lines. The alto in particular stays on C4 across three chords and never moves far. The point this example makes is that not every voice needs to be doing something dramatic.

four parts with no violations

Check

What does the alto do in Fig. 5?

Stays on C4 for three chords and moves only at VStays on C4 through all four chordsRises by step every timeMatches the motion of the bass

Check answer

▶ Write one yourself in the part-writing checker Set the number of chords to four and the degrees to I – IV – V – I, then place each voice by hand. Placing them manually rather than using auto-voicing is what makes the procedure mean something SATB Part-Writing Checker →

The next lesson takes up the classical exercise of building four parts from nothing but a bass line and figures — realizing a figured bass.