Free interactive music theory tools

Reading about theory and hearing it are different activities, and the second one is what actually changes your playing. These tools exist so that every essay on this site can point at something you can click.

The four tools

Interactive circle of fifths

Click any key to see its scale, its relative minor, its key signature, and the progressions that come from it. Play the scale or any common progression in that key. This is the tool most people should start with, because it makes the relationship between keys visible and audible at the same time. Open the circle of fifths →

Ear trainer

Interval recognition, chord quality, and scale-degree identification, with a proper key-establishing cadence before each item. That last detail matters more than it sounds: training intervals in isolation transfers poorly to real music, and training scale degrees in a key transfers well. Open the ear trainer →

Chord progression generator

Choose a key and a progression, hear it played back, and see the Roman numerals as it goes. Useful for songwriting, for checking what a progression sounds like before you learn it, and for training progression recognition. Open the generator →

Note identifier quiz

Staff note recognition in both treble and bass clef, including the ledger lines around middle C where nearly everyone is weakest. Timed or untimed. Open the note identifier →

How they are built

• Vanilla JavaScript and the Web Audio API. No heavy framework, so they load fast on a phone.
• Keyboard navigable throughout, and usable with a screen reader.
• Nothing is stored about you. Progress lives in your browser and goes no further.
• Everything works offline once loaded, apart from the first audio sample fetch.

Where to start

1. If you are new to theory: the circle of fifths, alongside music theory basics.
2. If you can read but cannot hear: the ear trainer, fifteen minutes daily, alongside solfege.
3. If you can hear but cannot read: the note identifier, alongside how to read sheet music.
4. If you write songs: the progression generator.

There are also printable reference charts as direct PDFs, with no email capture.