Chords of a key
The chords of a key, called diatonic chords, are built by stacking thirds on each degree of the scale using only the notes of that scale. Every key has seven of them, labelled with Roman numerals from I to VII.
Pick a key and play the chords that come from its seven degrees. They are the building blocks of most songs.
C major
- Key signature
- no sharps or flats
- Relative key
Tap a chord to hear it, or use keys 1 to 7 on your computer.
R = root position · 1, 2 = first and second inversion · 7 = seventh chord
How they work
Stack two thirds on each note of a scale, using only the notes of that scale, and you get seven triads: the diatonic chords of the key. In every major key their type is always the same: major on the first, fourth and fifth degrees, minor on the second, third and sixth, diminished on the seventh.
Roman numerals show the degree: upper case for major chords, lower case for minor ones. That way a progression such as I – V – vi – IV can be described once and played in any key.
Chords: How chords are built, from triads to ninths, to see and hear.
Frequently asked questions
- What do Roman numerals mean in chords?
- They show the scale degree the chord is built on: upper case for major chords (I, IV, V), lower case for minor chords (ii, iii, vi), with the ° sign for the diminished chord (vii°). They let you describe a progression in any key.
- What are the chords in G major?
- G, A minor, B minor, C, D, E minor and F sharp diminished. As seventh chords: Gmaj7, Am7, Bm7, Cmaj7, D7, Em7 and F♯m7♭5.
- What is an inversion?
- It is a chord whose lowest note is not the root. In first inversion the third is in the bass, in second inversion the fifth: C major in first inversion is E G C.
From theory to practice
With GEN you generate ever-new exercises on the scales you are studying.