Chords and voicing

Lab: Four of the same chord · Edit a musical idea

Starts with: four chords played one after another. All four are made of the notes C, E, G and B.

Reader controls: play each; show/hide the keyboard and piano-roll view.

Shows: keyboard and piano roll side by side, with the notes hidden at first.

Ask before revealing: "Which of these do you think is the 'real' C major seventh?"

Fallback: four clips and a keyboard diagram for each voicing.

Owner: Symbolic harmony explorer (voicing editing to confirm).

Listen to all four. One sounds dreamy and open. One sounds dense and a bit cloudy. One sounds bright, like a jazz pianist. One sounds dark and heavy.

Now reveal the notes. Every one of them is Cmaj7: C, E, G and B. Same chord name, same four notes. Four quite different feelings.

So what changed?

Try it: move the notes around

Lab: Build a voicing · Edit a musical idea

Starts with: Cmaj7 in close position: C4, E4, G4, B4.

Reader controls: drag any note up or down an octave; play.

Shows: keyboard and piano roll; the lowest and highest notes are highlighted and labelled "bass" and "top".

Ask: "Move only the lowest note up an octave. Does the chord feel more stable or less?"

Fallback: before/after clips for each suggested move.

Try these moves one at a time:

Move the C up an octave, so E is now the lowest note. The chord feels lighter and less settled, as if it's leaning somewhere.
Put it back, then drop the G down an octave, under the C. The notes spread out and the chord opens up. This one has a name, a drop 2 voicing, because you dropped the second note from the top.
Move the whole chord down two octaves in close position. It turns to mud.

What just happened

A chord name like Cmaj7 tells you which notes to play. It doesn't tell you where to play them. That choice is called the voicing, and three things about it matter most:

The bass note. The lowest note is the one the ear treats as the chord's foundation. When the root (C) is in the bass, the chord feels settled. When another note is in the bass, it's an inversion, and the chord feels lighter or more in motion.
The top note. The highest note is the one people tend to hear as the tune. Change the top note and the chord seems to "say" something different, even with the same notes underneath.
Spacing. Notes bunched together (close voicing) sound dense and unified. Notes spread out (open voicing) sound airy and spacious.

Same idea, different place: a chord symbol keeps the note names and throws away the voicing. That's a general rule about representations: every way of writing music down keeps some things and drops others. See Music as data.

Why low chords get muddy

Why did the close chord turn to mud when you moved it down?

In the low register, notes a third apart are very close in frequency. C2 is about 65 Hz and E2 is about 82 Hz, only 17 Hz apart. When two tones are that close, the ear can't fully separate them, and you hear a rough, buzzy quality called roughness. Higher up, C5 and E5 are about 523 and 659 Hz, far enough apart to sound clean.

That's why arrangers tend to spread the low notes out (a root and fifth, or a root and octave) and save the close intervals for the middle and top. How rough something sounds also depends on the instrument's tone and on taste. Some music uses low, dense clusters on purpose, for weight and growl. Treat "spread it out down low" as a reliable starting point, not a law.

Same idea, different place: roughness is the same effect as the beating you hear when two strings are slightly out of tune, and it's something Balinese gamelan tuning uses deliberately. See Tuning systems.

From chords to motion: voice leading

Voicings matter most when chords move. Here's one of the most common progressions in pop: C, Am, F, G.

Lab: Jumping versus gliding · Listen and compare

Starts with: the progression C, Am, F, G played twice, with a simple melody on top.

Version A (jumping): every chord in root position, close voicing, so all three notes leap together.

Version B (gliding): C4 E4 G4 → C4 E4 A4 → C4 F4 A4 → B3 D4 G4.

Reader controls: A/B switch; show lines connecting each voice from chord to chord.

Ask: "Before you look at the lines, which version do you think moves the notes less?"

Fallback: two clips and a piano-roll image with the connecting lines.

In version A, every note jumps each time the chord changes. In version B, look at the lines: from C to Am, only one note moves (G up to A). From Am to F, again only one (E up to F). From F to G, each note moves by a step or two.

This is voice leading: treating each note of the chord as its own little melody, and keeping those melodies smooth. Two tricks do most of the work:

Keep shared notes where they are. C and Am share C and E. Don't move them.
Move the rest by the smallest step. If a note has to change, find the nearest note in the next chord.

Many listeners hear version B as smoother and more connected, and it leaves more room for the melody. Version A isn't wrong. Big parallel jumps have a bold, blocky sound that's right for some styles, like power chords in rock. It's a choice, and now you can make it on purpose.

Our take: when a progression sounds stiff, revoice before you reach for new chords. The chords are often fine; the voicing is doing the damage.

Where it breaks

Smooth voice leading can drift. Keep choosing the nearest note and after a few chords the whole progression may have slid too low (mud again) or too high (thin and shrill). Watch the range, and when it drifts, reset with one deliberate jump at a section change, where a leap sounds intentional.

Also watch the top note against your melody. If the chord's top note clashes with the melody or doubles it awkwardly, voice the chord below the melody instead.

Make it yours

Take this progression: Am, F, C, G.

Voice the first chord however you like, in the middle of the keyboard.
Voice each following chord by keeping shared notes and moving the rest to the nearest chord note.
Check the range: is anything sliding too low or too high?
Play the supplied melody on top. Does any chord's top note fight it? Fix it.

Save your progression as a MIDI clip and play it through a pad and through a piano. Voicings that sound great on one instrument can sound different on another, especially in the low register.

[Open this progression in the studio] (planned link: opens the progression on a piano-roll with a keys instrument)

Quick check

Two players both play "Fmaj7". One sounds heavy, one sounds airy. Name two things that could be different.
Answer
Any two of: the bass note (root or inversion), the spacing (close or open), the register (low or high) or the top note.
Your chord sounds muddy in the left hand. What's the first change to try?
Answer
Spread out the low notes, for example root and fifth, and move the thirds and sevenths higher up.
Going from C (C E G) to Am, which notes can stay where they are?
Answer
C and E. Only G needs to move, up a step to A.

Next steps

Go deeper: Progressions and harmonic movement. You made chords move smoothly; next, why some progressions feel like they're going somewhere.
Use it: Bass lines and counterlines. The bass note you've been choosing can become a line of its own.
Sideways: Tuning systems. Roughness, beating, and why some musical traditions tune to make it shimmer.

Go deeper

Representations. The labs show keyboard and piano roll; staff notation and chord symbols can be added as further views. A chord symbol records pitch classes and, sometimes, the bass note (as in C/E). It doesn't record spacing, register or the top note.

Roughness. The low-register explanation draws on research into sensory roughness and critical bands. Roughness is one perceptual factor; it isn't the same as dissonance in a musical sense or as preference.

Sources and examples. All progressions and melodies are original examples for this guide. Frequencies are for 12-tone equal temperament at A4 = 440 Hz.