A chord inversion is the same chord with a different note in the bass. You make one by taking the lowest note and moving it up an octave, so the same notes end up stacked in a different order. The chord keeps its name and its notes; only the order and the bottom note change. Here is what root position, first and second inversion mean, worked out from a C major triad, and why inversions are so useful for making chords flow.
Real theory, explained plainly. It works the same on a piano, a guitar, or in a piano roll, in any key and any style. Nothing here needs a particular instrument.
A chord inversion is the same chord with a different note in the bass. You make one by taking the lowest note of the chord and moving it up an octave, which leaves the same notes stacked in a different order with a new note at the bottom.
Work it from a C major triad, whose three notes are C E G. In its plain form the root, C, is at the bottom. Move that C up an octave and E becomes the lowest note, giving E G C. Move the E up as well and G sits at the bottom, giving G C E. All three are the same chord, C major, built from the same three notes; only the order and the bass note have changed.
That is the key point: an inversion does not change what the chord is. It is still C major, still the notes C, E and G, and it still carries the same name. What changes is which note is lowest and how the chord is voiced. A plain triad has three notes, so it has three positions: root position and two inversions.
They are the three ways to stack a triad, named by which note sits in the bass. Root position has the root in the bass, first inversion has the third in the bass, and second inversion has the fifth in the bass. Here they are worked from C major, whose notes are C, E and G.
| Position | Bass note | Notes | Written as |
|---|---|---|---|
| Root position | C, the root | C E G | C |
| First inversion | E, the third | E G C | C/E |
| Second inversion | G, the fifth | G C E | C/G |
Root position has the root at the bottom. In C that is C E G, the plainest, most settled form of the chord and the one most theory starts from.
First inversion has the third in the bass. Move the root up an octave and the third, E, becomes the lowest note, giving E G C. It is often written C/E, a slash chord, which we come back to below.
Second inversion has the fifth in the bass. Move the third up as well and the fifth, G, sits at the bottom, giving G C E, written C/G. Every one of these is the same C major chord; the notes are the same, only the bass has changed.
A four-note chord has one more option. A seventh chord holds four notes, so it has a third inversion too, with the seventh in the bass. Take a C major seventh, C E G B, and put its seventh at the bottom and you get B C E G. Triads, having only three notes, stop at the second inversion.
Inversions matter mostly because they smooth out the movement between chords. Since an inversion changes which note is lowest without changing the chord itself, you can pick the voicing whose notes sit closest to the chord before it, so the parts shift a small distance instead of jumping.
That closeness is what people mean by smooth voice leading: when you move from one chord to the next, each note travels a short step, or stays put, rather than leaping across the keyboard. Choosing an inversion is one of the simplest ways to get it, and our guide to voice leading goes into it in more depth.
Inversions also give you a smoother bass line. If every chord sat in root position, the bass would jump to the root of each new chord. Inverting lets the bass step by small intervals from one chord to the next, or hold a note underneath a change, which tends to sound more connected.
There is a small change in colour and stability as well. Root position sounds the most grounded. A first inversion sounds a little lighter, and a second inversion, with the fifth in the bass, is often the least settled of the three and can sound as if it wants to move on. These are gentle shifts in feel rather than a change of chord, and the music around a chord can shade them, so treat them as tendencies, not rules.
You use an inversion by choosing the voicing that keeps a chord's notes near the chord on either side of it, then playing the bass note that voicing puts at the bottom. In a piano roll, or on the keys, that usually means moving the lowest one or two notes of a chord up an octave until the shape sits close to the chord before it.
A quick way to work is to look at where the last chord ended, then pick the inversion of the next chord whose notes overlap or sit nearest to it. Often only one or two notes need to move at all, and the run of chords starts to sound joined up rather than blocky.
When you want a specific note in the bass, write it with slash notation. A slash chord names the chord before the slash and the bass note after it, so C/E means a C chord with E in the bass, its first inversion, and C/G means a C chord with G in the bass, its second inversion. The letters before and after the slash are still the same C major notes; the slash just tells you which one to put at the bottom.
The shapes you are inverting are the plain triads, so it helps to know those cold first. Once you do, inversions are mostly a matter of deciding which note you want lowest and letting the rest fall into place.
We built ARGISH to make this quick to hear. It is a self-playing chord synth: set a key and it voices chords and whole progressions that stay in that key, choosing how each chord sits, so you can hear how an inversion smooths the move from one chord to the next instead of reading it on the page. It is a fast way to hear what inversions actually do in a progression.
It runs free in your browser to try, and installs as AU, VST3, AAX or a standalone app when you want it inside your own sessions.
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