Lesson 3 — Root Position Triads

Root Position

A triad in root position has its lowest note in the bass. If the triad is C-E-G and the bass plays C, it is in root position.

Root position is the most stable of all — it is the "resting position" of the chord.

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Root Position Doubling Rule

When writing a triad in 4 voices, we need to double one of the notes (because we have 4 voices and only 3 distinct pitches).

The general rule:

In root position, the root of the chord is preferably doubled.

Why the root? Because it is the note that defines the identity of the chord. Doubling it reinforces the sound without altering harmonic function.

Important exceptions:

• In the dominant chord (V), G can be doubled, but never double the leading tone (B in C Major)
• In augmented sixth chords, special rules apply

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The Common Tone: Voice Leading's Best Friend

When two consecutive chords share one or more notes, those notes are called common tones.

The Hernández Medrano method rule:

When two chords share a note, that note is retained in the same voice.

Example: I → IV in C Major

• Chord I: C-E-G
• Chord IV: F-A-C

The note C is common. If you had it in the Alto, keep it in the Alto for chord IV.

This technique produces smoother, more cohesive voice leading.

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The Leading Tone and Its Resolution

The seventh scale degree (B in C Major) is called the leading tone because it "feels" the gravitational pull of the tonic a semitone above.

In the V → I cadence:

• The leading tone (B) must resolve upward to the tonic (C)
• This applies especially when the leading tone is in the soprano

❌ Serious error: Letting the leading tone fall to G at the cadence is one of the most aesthetically unpleasant chorale errors.

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Fundamental Progressions

The most important root position progressions are:

• I → V → I (authentic cadence)
• I → IV → I (plagal cadence)
• I → II → V → I (complete progression)
• I → VI → IV → V → I (full functional progression)

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Exercise

Write I-IV-V-I progressions in root position in three keys: C Major, G Major, and F Major.

For each progression:

1. Respect vocal ranges
2. Double the root in each chord
3. Retain common tones
4. Correctly resolve the leading tone in the V→I cadence