Chords, scales, rhythm and harmony

Learn music theory by ear.

Look up what a chord, scale or groove actually does, in plain language, and hear it in the same breath. Everything on this site plays, so you learn what music sounds like and not just what it is called.

I - V - vi - IV in C majorI - V - vi - IV

Pick where you start

Start here18 lessons from the very first note. No notation and no prior knowledge.
Learn210 pages on chords, scales, harmony and rhythm, each one playable.
Practice16 ear training exercises, one question per screen with the reason behind the answer.

Play it yourself

Two labs: piano chords and drum grooves

Everything you read about here you can take apart yourself. Both labs run on our own synthesis in the browser, so a chord you want to try costs one click.

Pianolab27 chord typesEvery chord type on all twelve roots, inversions included, on one keyboard you click. The notes appear on a staff beside the keys, and each chord links to the page that explains it.Open the Pianolab Drumlab12 style groovesPlace hits in a sixteen step grid with nine sounds and hear the bar go round. Start from a style groove, then move the tempo and the swing until it sits where you want it.Open the Drumlab

Never done this before

18 music theory lessons for complete beginners

No notation, no prior knowledge, and nothing you have to take on faith. Every lesson is something you press: you count the half steps yourself, you build the chord, you hear what changes. Take them in order or open the one you came for.

Start with lesson one

What a note is
The distance between two notes
Why some notes clash
What a chord is
The four kinds of triad
and 13 more, up to reading from the page.

Practice

Ear training for chords, intervals and rhythm

You can explain exactly what a minor chord is and still not recognize one in a song. That gap is what the exercises are for. Every explanation has one beside it, and every exercise links back to the page it came from.

Everything playable

The music theory knowledge base

From your first chord to modal harmony. The four biggest sections are below, and every other one sits underneath them. All of it plays.

Chords

26 pages

Per chord: how it sounds, where it wants to go and when to use it. Inversions included.

Scales

21 pages

Major, minor, pentatonic, blues and every mode. The characteristic note that creates the feeling switches on and off.

Progressions

27 pages

The engine under every song, with the story behind it: why it works and which pile of songs leans on it.

Harmony

17 pages

Why one chord follows another: function, tension, cadences and the moment a song comes home.

Why Akousia exists

Why music theory sticks when you can hear it

Music theory is almost always taught with names and staves. That is how I learned it. It took years before I could hear what those names actually meant.

So every page here starts with the sound. You hear what happens, and the name sits beside it for when you need it.

What this should become is the place where anyone, nine or ninety, can find out how music actually works. Not a course you enrol in and not a method you have to believe in. A place where a question takes one click to answer, out loud, and where the answer makes the next song you hear sound different.

About Akousia

Everything playsNo page goes live without something you can hear.
No accountNothing to sign up for. Your settings sit in the link, so you can hand that link to anyone.
Our own synthesisWe make all the audio ourselves, so no samples and no clips from other people's recordings.