Inversion
An inversion is a chord played with a note other than its root as the lowest note, so the chord keeps its name but changes its bass and its shape.
What does an inversion look like?
Take C major, C–E–G. Which note is lowest decides the inversion:
| Position | Bass note | Notes, bottom to top | Chord symbol |
|---|---|---|---|
| Root position | the root, C | C–E–G | C |
| First inversion | the third, E | E–G–C | C/E |
| Second inversion | the fifth, G | G–C–E | C/G |
A seventh chord has four notes, so it has one more: in third inversion the seventh is in the bass. G7 (G–B–D–F) with F at the bottom is written G7/F.
Only the bass matters. C–G–E and C–E–G are both root position, because C is still lowest; rearranging the upper notes changes the voicing, not the inversion.
How do you hear an inversion?
Listen to the bass on its own. Root position sounds the most settled, and it is where pieces usually end. First and second inversions sound lighter and less finished, which is why they turn up in the middle of a phrase.
The clearest place to hear them is a bass that walks by step. A bass going C, B, A under the chords C, G/B, Am uses the G chord in first inversion so the bass can move one note at a time instead of leaping.
What is the most common confusion?
Treating an inversion as a different chord. E–G–C is not an E chord: it is C major with E in the bass. Name the chord from its three notes, then name the inversion from the bottom one. Those are two separate questions.
Try it: the inversions lesson mixes all four chord qualities with inversions turned on, and Building chords has you play the same chords with a different note in the bass on your own instrument.