Free tool

Chord Progression Analyzer: Why Does This Progression Sound Good?

Type your chords and find out why they sound the way they do, then get ideas to try.

1 · Your chords

Write an inversion as a slash chord: D/A is D with A in the bass (the notes A D F♯).

Key

How do you play it?

The bass note is the lowest note, so a slash chord is a true inversion. Switch to the first option if your left hand plays the roots.

What you have · reads as G major

D/AV⁶₄tension · second inversionA D F♯
Amiiaway · root positionA C E
C/GIV⁶₄away · second inversionG C E
GIhome · root positionG B D

Bass line: A – A – G – G (degrees 2 2 1 1)
Top notes: F♯ – E – E – D (degrees 7 6 6 5)

Voicing assumed: the chord notes close together with the bass lowest, in whichever octave keeps your hand still.

2 · Why it sounds the way it does

Every chord comes from G major
All 4 chords are built from the notes of G major, so nothing in the music is foreign. The chords feel like a family because they draw on one shared scale, and each one is a note or two away from the next.
The bass walks, it does not jump
The bass note only changes once, and only by step: A – A – G – G (scale degrees 2 2 1 1). Some chords sit over the same bass note, so the bottom of the music stays still while the chords above move: that is a pedal point, and it makes changing chords feel like the same ground with new light on it. In root position the bass would leap 3 times (D – A – C – G). The inversions are what smooth it out.
The voices barely move
Played the way a pianist would hold them (chord notes close together, bass lowest), every note either stays where it is or moves by a single step, and 4 notes stay put across the changes. The chords share 1 note (A) between D/A and Am, 2 notes (C E) between Am and C/G and 1 note (G) between C/G and G. When the ear can follow each line smoothly, the change sounds inevitable, not sudden.
The top notes sing a little tune: F♯ – E – E – D
The highest note of each chord goes F♯ – E – E – D (scale degrees 7 6 6 5), a gentle fall, like a sigh moving only by step. Your ear hears this as a melody sitting on top of the chords, which is a large part of why it feels like a song and not a list of chords.
The story in Roman numerals: V⁶₄ – ii – IV⁶₄ – I
It opens on tension rather than home, so it leans forward from the first chord. V⁶₄ to ii: Tension steps back to a chord that normally comes before it. This "retrogression" loosens the pull of V: the song floats instead of pushing forward, a favourite in pop. IV⁶₄ to I: The "amen" move: away to home, softer than V to I. It settles without any drive. It ends at home, so it feels resolved.
D/A over a held bass
D/A has its 5th in the bass (a "six-four" chord), and the bass then stays put while the chord changes above it to Am. The upper notes fall by step onto their neighbours while the bass holds still: a suspension-like sigh that classical and pop writers have used for centuries. It is also why such chords feel like they are waiting for something.
What happens to the leading note
D/A contains the 7th note of the scale (F♯), the "leading tone" that normally climbs a half step to the tonic. Here it drops by a step instead (F♯ to E), which takes the urgency out of the chord: it relaxes instead of pushing home.
What the loop does
Played round and again, I goes to V⁶₄: Home to tension: a strong push forward that begs to come back.

Chord by chord: what each change does

D/A → Am
Roots move up a fifth · bass stays · shared notes: A
Tension steps back to a chord that normally comes before it. This "retrogression" loosens the pull of V: the song floats instead of pushing forward, a favourite in pop.
Am → C/G
Roots move up a third · bass steps · shared notes: C E
Staying away from home, with a change of colour.
C/G → G
Roots move up a fifth · bass stays · shared notes: G
The "amen" move: away to home, softer than V to I. It settles without any drive.
G → D/A(back to the start)
Roots move up a fifth · bass steps · shared notes: D
Home to tension: a strong push forward that begs to come back.

Home: Settled and at rest. The song feels at home on these. Away: Leaves home and heads towards the tension chord. Tension: Tension that wants to resolve back home.

3 · Things to try next

Each one changes a little and explains why it should still feel right. Hear it, and keep what you like.

same feeling
Add one note to every chord
D7/A Am7 Cmaj7/G Gmaj7
Same chords, same bass, one extra note each. The extra notes are the kind the key already likes, so the feeling stays and the sound gets softer. D7: The 7th adds extra pull towards I. This is the most common upgrade of all. Am7: The standard colour for ii: smooth and mellow, and it leads beautifully to V. Cmaj7: Warm and floating: the most popular colour for IV.
decoration
Hang D/A with a suspension
Dsus4/A D/A Am C/G G
Dsus4/A swaps the 3rd for the 4th for a beat, then the 4th falls onto the 3rd as D/A arrives. Same chord, same bass, but the arrival is now something you waited for.
swap
End on Em7 instead of G
D/A Am C/G Em7
Em7 contains every note of G plus the 6th, so it is the same harmony turned wistful. The landing is softer and less final. Feels like the song could go on.
colour
Land on Gadd9
D/A Am C/G Gadd9
Adds an open, airy note on top without changing the chord's job. Very common in modern pop and worship.
borrowed
Borrow the minor Cm
D/A Am Cm/G G
Swap C/G for Cm/G, the IV chord of the parallel minor. Its third drops a half step (E to E♭), a bittersweet note that falls into the next chord. The most loved "borrowed chord" in pop and film music.
borrowed
Add F (♭VII) before the end
D/A Am C/G F G
F sits a whole step below home and is built on a note just outside G major. Rock and folk use it constantly: it sounds like a wide-open road into the home chord.
swap
Bm in place of D
Bm Am C/G G
Bm shares 2 notes with D, so it is a close relative. It changes the job from tension to home, so expect a different feeling at that point.
swap
Em in place of C
D/A Am Em/G G
Em shares 2 notes with C, so it is a close relative. It changes the job from away to home, so expect a different feeling at that point.

Notes to try over each chord (melody, fills, a right-hand line)

D/A
Chord notes: D F♯ A
Colour notes from the key: B (the 6th), C (♭7), E (the 9th)
Pass through, do not rest on: G (the 11th) (a half step above a chord note, so it grinds unless it resolves down)
Am
Chord notes: A C E
Colour notes from the key: G (♭7), B (the 9th), D (the 11th), F♯ (the 6th)
C/G
Chord notes: C E G
Colour notes from the key: A (the 6th), B (the 7th), D (the 9th), F♯ (♯11)
G
Chord notes: G B D
Colour notes from the key: A (the 9th), E (the 6th), F♯ (the 7th)
Pass through, do not rest on: C (the 11th) (a half step above a chord note, so it grinds unless it resolves down)

These are readings and suggestions, not rules: music is fluid, and if you like how it sounds, it is right. To dress the chords up in more detail try Reharmonise, or read when to use 7ths, 9ths and sus chords.

Find out why your chords sound the way they do

Type the chords you are playing, with inversions written as slash chords, and the analyzer reads the key, names each chord's job (home, away or tension), follows the bass line and the top notes, and counts the notes that stay still between chords. Then it puts the result into plain words: which of these things makes your progression feel smooth, bittersweet, open or settled.

What it looks at

The key. Chords that all come from one scale feel like a family. A chord from outside is a splash of colour.
Function. Home chords (I, vi) rest. Away chords (ii, IV) lean towards tension. Tension chords (V) want to resolve. Tendencies like the plagal "amen" or a V that steps backwards to ii change how forward-moving the music feels.
The bass. A bass that walks by step, or stays put under changing chords (a pedal), makes changes feel gentle. Inversions are the tool for this.
Voice leading. When each note moves by a step or stays, the ear follows every line and the chord changes sound inevitable.
The top line. The highest notes of a progression often form a small melody of their own.

Then try something

Below the analysis you get ideas that keep the feeling (an extra note on each chord, a suspension, an inversion that smooths the bass) and ideas that change the light on it (a borrowed chord from the parallel key, a close relative in place of one chord). Hear each one, then tap Analyse this to see why it works. For more detailed dressing-up of the chords, use Reharmonise; to understand the colours, read when to use 7ths, 9ths and sus chords, or learn inversions and slash chords.

Frequently asked questions

Why does a chord progression sound good?

Usually a mix of a few things: all the chords share one key, the bass line moves smoothly (often by step), chords next to each other share notes so the voices barely move, the top notes form a little melody, and the chords tell a story of leaving home, building tension and settling. The tool checks each of these and tells you which ones your chords have.

How do I write an inversion?

As a slash chord. D/A means a D chord with A in the bass, so the notes are A, D and F♯ (second inversion). C/E is C with E in the bass (first inversion). Without a slash the chord is in root position.

What do Roman numerals like V⁶₄ mean?

The numeral says which step of the key the chord is built on (I is home, V is the dominant). The small numbers say which note is in the bass: ⁶ means the third is in the bass (first inversion), ⁶₄ means the fifth is in the bass (second inversion).

Why does the key sometimes show two answers?

A major key and its relative minor use exactly the same notes (C major and A minor, for example). A short progression can fit both, and which one sounds like home depends on where you rest. That ambiguity is a source of the bittersweet sound of many hit progressions.

Is there a right answer?

No. This is a reading of what the ear is probably picking up, and the suggestions are ideas to try. Music is fluid: if you like how it sounds, it is right.

My left hand plays the root and my right hand plays an inversion. Does that count?

Yes, and it is the most common way to play piano. Choose "Left hand root, right hand chord" and pick the right-hand inversion for each chord (or leave it on Auto for the smoothest). Strictly, an inversion means the lowest note is not the root, so with a root in the left hand the chord is still in root position, but the right hand moving smoothly is what makes the progression glide.

What voicing does it assume?

The chord notes stacked close together with the bass note lowest, placed in whichever octave keeps your hand closest to the previous chord. That is how most players naturally play a progression on piano.