A chord chart tells you almost nothing about how to play it. Am – G – F – G is four symbols; a pianist turns them into two hands doing different jobs, in a particular register, with the pedal moving. This is how that translation actually works.

Most people who write chords at a keyboard get stuck in the same place: the left hand plays the root, the right hand plays the chord, and everything sounds like a hymn. The fix is not more chords. It is understanding that the two hands are not playing the same thing at different pitches. They have separate responsibilities, and once you separate them, the same four chords can be a ballad, an underscore or a full cinematic build.

What each hand is for

The left hand carries the harmony and the time. It tells the listener which chord we are on and where the beat is. It does not need to be interesting; it needs to be unambiguous. Nearly all left-hand writing is some arrangement of root, fifth and octave, plus occasional passing motion between chords.

The right hand carries the motion and the colour. It provides rhythmic life and the notes that give the chord its character: the third, the seventh, the ninth, the suspension. It is where the music happens.

When an accompaniment sounds muddy or dull, it is almost always because one hand is doing the other's job: a left hand playing full chords in the middle register, or a right hand hammering out roots that the left hand already covered.

Left hand: which chord, and when. Right hand: how it feels.

Left-hand patterns, in order of weight

Root only

One note per chord, low, usually on the downbeat. The most transparent option and the correct default under a busy right hand or a vocal. Sustained, it leaves the whole middle register free.

Root and fifth

The open fifth: root plus the note seven semitones above. Slightly more body than a single note, still no third, so it does not fight whatever the right hand does with the harmony. Plays well in low registers where a third would turn to mud.

Octaves

Root doubled an octave up, both struck together. This is the weight option, from a rock ballad to the low end of a cinematic cue. Two octaves apart rather than one gives more air and less thickness.

Broken octave or fifth

Root on the beat, fifth or upper octave on the off-beat. Creates motion without any extra notes. The workhorse of ballad writing, and it converts a static left hand into a pulse without touching the harmony.

Arpeggiated tenths

Root, then the third an octave and a bit above it, a tenth, then back. The interval is wide enough that the third does not muddy, and it gives the left hand the harmonic colour that root-and-fifth patterns lack. This is the sound of a great deal of jazz and of cinematic piano writing, and it is the single most useful upgrade to a plain root pattern.

Walking bass

Stepwise or scalar motion connecting the root of one chord to the root of the next. Best used sparingly, one walking bar in eight, because it pulls attention downwards and that is usually not where you want it.

Right-hand patterns

Block chords

The whole chord struck at once. Direct, and correct when the rhythm itself is the idea. The reason block chords often sound amateur is not the technique but the voicing. See the section on inversions below.

Broken chords

The notes of the chord played one after another rather than together. The difference between an accompaniment that plods and one that flows.

Arpeggios

A broken chord that spans more than an octave and keeps moving in one direction. Up-and-down arpeggios are the default and the most easily overused; the shape becomes predictable within two bars. Breaking the contour, so the pattern goes up-down-up rather than straight up, keeps it alive far longer.

The Alberti figure

Low–high–middle–high, repeated: over C major, C–G–E–G. Classical, and still useful in film writing when you want busy motion that is harmonically completely neutral. It is the pattern most likely to sound dated, so it usually wants a modern register or texture around it.

Syncopated pad

The chord struck on the off-beats and held. Almost nothing happens rhythmically, but the music pulls forward against the left hand. This is how a great deal of contemporary underscore achieves motion without anything obviously moving.

Ostinato figure

A short repeating pattern that does not change shape as the harmony moves under it. The right hand of most cinematic piano writing is an ostinato rather than an accompaniment in the classical sense. The figure is the constant and the chords move beneath. The guide on writing a cinematic ostinato covers how to build one that stays alive over a long build.

Inversions: the biggest single upgrade

Play Am – G – F – G in root position, both hands, and every chord jumps. The right hand leaps around, the harmony sounds blocky, and it is obvious that someone is reading symbols rather than writing music.

The fix is voice leading: choose the inversion of each chord that moves the least from the one before it. Concretely, for the right hand:

• Am: A, C, E (root position)
• G: B, D, G (first inversion; B and D are a step from A and C, G stays near E)
• F: A, C, F (second inversion; A and C are already there from the Am)
• G: B, D, G again

Now the top voice moves E – G – F – G, and the inner voices barely move at all. Same chords, same order, completely different music. It sounds arranged rather than typed, and the reason is that the ear follows individual lines, not chord labels.

Spacing: the muddy zone

The most frequent technical fault in piano writing is putting thirds too low.

Below roughly C3, the C an octave below middle C, intervals smaller than a fifth start to beat against each other and sound thick rather than rich. This is physics rather than taste: the lower the fundamental, the wider the harmonic series spaces out, and closely-spaced low notes produce harmonics that clash.

Practically: below C3, use octaves, fifths and tenths. Between C3 and C4, thirds and sixths are fine. Above C4, voice as closely as you like. Close seconds up there read as colour rather than mud. Look at any piano score you admire and you will find this shape: wide at the bottom, tight at the top.

The pedal

The sustain pedal is not an effect applied to the piano. It is a part, and it has its own rhythm.

Harmonic pedalling

The default: change the pedal on every chord change. Down on the downbeat, up an instant before the next chord, down again. Everything from the current harmony rings; nothing from the previous one carries over. If you learn one thing about the pedal, learn that the change happens after the new chord is struck, not with it. A fraction late, so the old harmony is caught and cleared while the new note is already sounding.

Rhythmic pedalling

Changing more often than the harmony does, on every beat or every two beats, even when the chord stays the same. Keeps a repeated chord from accumulating into a wash. Useful under fast right-hand figures.

Half-pedal

The pedal held partway, so low strings continue to ring while the upper register clears. On a real piano this is a continuous control, not a switch. In a MIDI mock-up it is the difference between a sustain value of 64 and one of 127, and most piano libraries respond to it.

The long pedal

Held through a chord change on purpose, so two harmonies blur together. Impressionistic, deliberate, and the single fastest way to make a simple progression sound sophisticated. It only works when the two chords share most of their notes, Am into F for instance. Hold a pedal through Am into B♭ and it is just a mistake.

The failure everyone makes: pedalling down on the downbeat and not lifting until the end of the bar, regardless of what happened in between. Two chords ring together, the bass smears, and the whole thing sounds like it was recorded in a stairwell.

Patterns by style

Pop ballad

Left hand: root octaves on beat 1, fifth on beat 3. Right hand: broken chord in eighths, top note held slightly longer. Pedal changes with each chord. Keep the right hand between C4 and C5 so there is room for a vocal above it.

6/8 cinematic

Left hand: root on beat 1, fifth on beat 4 of the six. Right hand: three notes per dotted-quarter, rocking. The compound metre is what gives this its particular lift; the same chords in 4/4 sound entirely different.

Minimal / contemporary classical

Left hand: single low notes, long, one per bar or less. Right hand: a four- or five-note repeated figure, always the same rhythm, with the notes adjusting to each chord. Very little dynamic variation within a bar; the shape is across sixteen bars rather than within one.

Driving cinematic

Left hand: octaves in quarters, relentless. Right hand: eighth-note ostinato with one gap per bar. Both hands at least two octaves apart. This is the piano writing that sits inside an orchestral build. It wants to be a rhythm-section instrument, not a soloist.

Sparse underscore

Left hand: nothing for bars at a time. Right hand: two or three notes, high, widely spaced, with long gaps. Pedal held long. Almost no motion. This is a colour rather than an accompaniment, and its power comes from restraint.

Dynamics and phrasing

An accompaniment played at one dynamic sounds like a machine, but the fix is not random variation.

Two shapes do most of the work. Within the bar, notes get slightly louder as the line rises and softer as it falls: five to ten velocity steps, no more. Across the phrase, four bars grow and four bars recede, typically peaking in the third bar of a four-bar unit rather than the last.

The left hand should sit consistently below the right, commonly ten to twenty velocity steps under it. A left hand at the same level as the right is the most common reason a mock-up sounds bottom-heavy.

Turnarounds and fills

A four-bar loop played eight times is eight loops. A four-bar loop where the fourth bar is slightly different every other time is a sixteen-bar phrase, and the listener hears it as writing rather than repetition.

The turnaround is the last bar of a phrase, and it has one job: to hand over to the next phrase. Three reliable versions:

• Walk the bass. Instead of holding the root for the whole bar, step from the current root down or up to the next one. Two extra notes, and the phrase now leans forward.
• Thin out. Drop the right hand for the second half of the bar. The silence is the handover.
• Add a suspension. Hold the fourth over the final chord and resolve it on the downbeat of the next phrase. The resolution happens across the bar line, which stitches the two phrases together.

A fill is the same idea with more notes: a short run in the right hand in the gap left by a held chord. The discipline is to keep it inside the register you have been using. A fill that suddenly leaps two octaves higher announces itself, and an accompaniment should not.

Writing it as MIDI

Everything above assumes a player. If the part is going to be programmed, four details separate a mock-up that sounds played from one that sounds entered.

Note lengths. A pianist's notes overlap slightly, because the hand does not leave one key until the next is already down. Notes that end exactly where the next begins sound mechanical. Extending each note by twenty to forty ticks past the next onset fixes most of it, and it matters more than velocity does.

Timing offsets. Real hands do not land together. The left hand usually arrives a few milliseconds before the right on a downbeat, and the top note of a rolled chord arrives last. Shifting the melody note five to fifteen milliseconds late against the rest of the chord is the single most convincing adjustment available. It is how a phrase gets a sense of weight.

The pedal is CC64, and it is continuous. Most libraries respond to intermediate values, not just 0 and 127. Writing the pedal as a curve rather than a switch gives you half-pedalling, and it removes the abrupt cut that makes programmed piano sound programmed. The pedal-up should land just after the new chord, not with it, by the same fraction of a beat a player would use.

Velocity ranges, not velocity values. Most piano libraries change timbre with velocity, not just volume. A part written entirely between 70 and 80 will sound like one sample layer throughout. Using the full range, 35 for the quiet passages and 105 for the peaks, is what makes a library instrument sound like an instrument.

Common mistakes

• Both hands in the same octave. They fight for the same frequency range and the texture collapses. Keep at least an octave and a half between the top of the left hand and the bottom of the right.
• The right hand doubles the melody. If there is a vocal or a lead line, the accompaniment should support it, not shadow it. Doubling makes both sound weaker.
• Every chord in root position. Covered above. This is the one worth fixing first.
• Pedal held through a harmony change. The most audible flaw in any mock-up.
• The pattern never changes for three minutes. Even a tiny variation is enough to keep the ear engaged: drop the left hand for two bars, or thin the right hand at the turnaround.
• Too many notes. A four-note chord in each hand is eight notes sounding at once. Three and two is usually better, and leaves room for everything else in the arrangement.

A worked example

Am – G – F – G, 4/4, 72 BPM, ballad feel. Four bars, one chord per bar.

Left hand

Broken octaves. Beat 1: the root, low. A2, G2, F2, G2. Beat 3: the same note an octave up. A3, G3, F3, G3. Nothing else. The lower note is held with the pedal; the upper one is short.

Right hand

Voice-led as above: Am (A4–C5–E5), G (B4–D5–G5), F (A4–C5–F5), G (B4–D5–G5). Play each chord broken, lowest to highest, in eighths, with the top note struck again on the last eighth of the bar so the phrase leans into the next chord.

Pedal

Down just after beat 1 of each bar, up just before beat 1 of the next. On the last bar, hold it through into the repeat so the G and the returning Am blur. They share the note G, so the blur is consonant.

Turning it cinematic

Same four chords. Move the left hand to full octaves in quarters instead of broken halves. Move the right hand up an octave and turn the broken chord into a repeating six-note figure that keeps its shape as the harmony changes. Add a low root two octaves below the left hand on the downbeat of bars 1 and 3 only.

Nothing about the harmony changed. The piece went from a ballad to something that would sit under picture, and the only decisions were register, rhythm and density, which is what an accompaniment is.

Where a tool fits

The judgement calls above are the writing, and they stay yours: which pattern, which register, how the pedal moves, when to thin out.

The part that is not writing is the transcription: taking a pattern you have decided on and laying it correctly across a progression, hand by hand, checking each note against the chord underneath it, keeping the voice leading tight, and putting the pedal changes where the harmony moves.

That is what Piano does. Left hand and right hand as separate parts, the accompaniment below and the melody on top, pedal written into the exported MIDI and moving with the harmony, and every note editable once it lands in your DAW. It writes the part a player would play, so you can spend your time on the decisions that matter rather than on the typing.