Chord Inversions

A chord is a group of notes sounded together, but the same chord can be stacked in more than one order. When a note other than the root sits at the bottom, the chord is inverted. This lesson shows how the three positions of a triad work and why voicing the same harmony differently is such a useful tool.

Root position and inversions

A triad has three notes: the root, the third, and the fifth. Which of them is the lowest sounding note decides the position. Take a C major triad, built from C, E and G.

• Root position: the root is on the bottom, so C E G (C is lowest).
• First inversion: the third is on the bottom, so E G C (E is lowest).
• Second inversion: the fifth is on the bottom, so G C E (G is lowest).

In every case it is still a C major chord. The letters C, E and G never change; only the order of the pitches from low to high does. That is the key idea: inversion changes the voicing, not the identity of the harmony.

Figured bass and roman numerals

Musicians label these positions with figured bass numbers, which count the intervals above the lowest note. Root position is a fifth and a third above the bass, written 5/3 but usually left unmarked. First inversion is written 6 (short for 6/3), and second inversion is written 6/4. Attached to a roman numeral, a C major chord acting as the I chord appears as I, I6, and I64.

Why inversions matter

Inversions are not just theory bookkeeping. They give you control over the bass line, the lowest voice that listeners hear most strongly. By choosing an inversion you can move the bass by a small, smooth step instead of a large leap, which makes progressions easier to sing and play. This is the heart of good voice leading.

Inversions also change the colour of a chord. A root position triad sounds solid and grounded. A first inversion sounds lighter and more mobile, often pushing the music forward. A second inversion can feel unstable and expectant, which is why it so often appears just before an important cadence.

Same three notes, three different feelings. Learning to hear the bottom note of a chord is one of the fastest ways to sharpen your ear.

Try it yourself below. Build a triad, then move its lowest note up an octave to hear the next inversion, and listen to how the character of the harmony shifts while the chord name stays the same.