Roman Numeral Chords
The chords built on each scale degree · pick a key & mode · tap to hear
How to play
- Roman numerals name a chord by its position in the key, not its letter — so the same progression works in any key. Pick a root and major/minor, and the seven chords fill in.
- UPPERCASE = a major chord, lowercase = minor, a ° after it = diminished, a + = augmented. So in C major: I = C, ii = Dm, vii° = B diminished.
- Tap a chord to hear it; Play all runs I–vii up the scale. Tap a progression chip to hear a common sequence in this key.
- Switch to 7th chords to see the four-note versions (Imaj7, ii7, V7, viiø7…) that give jazz its colour. The three key chords are I (home), IV and V (which pulls home). Vol sets volume.
This is a really useful tool that helps you explore seven chords that naturaly form part of each musical key. You can interact with it by clicking directly on the interface or by using your computer keyboard to trigger sounds and change settings. The other version are more direct, where you click on the interface itself to engage with it. Either way, it provides a quick reference point for the connection between scale and harmony: major and minor scales translated into harmony.
Firstly choose a root note from top row of buttons. Each button matches one of the twelve keys of music, from C to B. By default, this will begins with the key of C. Click on any other root button to change the whole chart to a different pitch. This lets you see how these chord relationships applies in keys more suited to your playing, instrument, or voice.
How to Use This Music Tool
To the right of the root selector is where you control the chord quality and mode. Turn the Major/Minor button on to listen to bright sound of a major scale or turn it off to hear the darker tone of a natural minor scale. Immediately, the diatonic chords changes to match the new scale intervals. Next, select Triad or 7th to make your chords more complex. Triads displays the underlying three note chords, but 7th chords shows you how these chords extend into the four note extensions frequently found in pop and jazz music.
In this example, the primary grid display the seven chords from the chosen key. This includes the Roman numeral, the real chord name and the function in the key. The Roman numerals is used for position, not pitch. Major chords use uppercase letters, while minor chords use lowercase letters. Diminished and augmented chords has a plus sign or degree symbol after them. This enables you to read music that isn’t dependent on transposition.
To listen to one of these chords, simply click on the box in the grid. The notes of the harmony are gently played as an audio sample. This allows you to isolate the sound of any single note or ‘scale degree’ in the chord. Pressing the button marked Play All will play all seven degrees of the scale from the tonic (I), through to the leading tone chord (vii). From this you can then hear how each degree changes colour and moves in a step wise manner within the context of the whole scale.
Below the main grid are some progression chips which is for common harmonic patterns. The buttons contains the usual sequence of chords such as ii-V-I or I-IV-V etc. When you click on one it will play the chords through in time and show how these static chord become phrases when played together. The mode setting above change between minor and major progressions.
To make the playback volume comfortabley with whatever is going on around you, simply move the slider at the lower right of the widget to adjust the sound. If you want to study the chart more closely, hit the Fullscreen button to make the widget full-screen in your browser. It’ll be a bit easier to see those labels and chord grid this way on smaller screens. Hitting the How to play button displays a short help panel that gives some quick reference notes on what everything means. This can be realy useful if you are revisiting the symbols after a timeout. It quickly explain what each thing does without having to go through them all again. Hit close once you’re done, and then get back into discovering the chords.
Listen out for additional colour if you try switching between triads and sevenths. For example, try playing the dominant seventh of a major key against the minor seventh of a minor key. You’ll notice that switching from one mode to another change the character of the leading tone chord.
If you’re using a MIDI controller, have a go on the keyboard as well or just use your mouse to activate the sound and learn the appearance of this layout. Begin with your chosen comfortable key and mode set to major. Create a sense of home with the tonic chord followed by a move to the dominant and subdominant. Hear what happens, how it works, feels, and resolves that feeling of tension. When you are happy with these, change to minor and notice the difference in the qualities of chords.
This is a great tool for learning more about music theory and growing your musical vocabulary. You should of tried it out sooner.