Chords are a fundamental aspect of music theory. They create the layers and rich harmonies. The mood and mode of a piece are in part determined by its chords.
A chord is simply three or more notes, played simultaneously or in a broken pattern. How those notes are arranged, and in what sequence they are stacked, determines what inversion that chord is in. We will examine three commonly used chord positions and inversions: root position, first inversion and second inversion. To invert a chord means simply to rearrange the notes of that chord.
A root position chord is made of three notes that are stacked a third, or a skip, apart. For instance, a C root position chord is made of C-E-G. The interval from C to E is a third, and from E to G is a third, as well. When a chord is in root position the bottom or first note is called the root note and names the chord. So, C is the root, E is the third tone (because it is a third above the root), and G is the fifth tone (because it’s a fifth above the root).
When a chord is inverted once, or is in first inversion, then that root note (in our example C) is moved an octave higher, while the other two notes, the third and fifth (E and G), stay in position. So now the root note (C) is the highest or top note of the chord, and, in this example, the sequence of notes played is E-G-C. Now the third tone is on bottom, the fifth is in the middle, and the root is on top. Also, the intervals between notes has been altered. We still have a third or skip between E and G, but now a fourth between G and C.
In a second inversion chord, the fifth tone is played on bottom, the root note in the middle, and the third tone on top. So a second inversion C chord would be G-C-E. And the intervals are a fourth (from G to C) followed by a third (from C to E).
Check out my lesson on Edvard Grieg’s “Morning Mood” – this simple arrangement uses chord inversions:
In conclusion, always know where your root note is within the chord. If all the tones are a third apart (root position) then the bottom note is the root note. If you have an interval of a third followed by a fourth, then the root note is at the top, and the chord is in first inversion. And if you have a fourth followed by a third, then the root note is in the middle, and the chord is in second inversion.