Learn music theory in a fun way, it's free!
an app for android and ios.

Easily learn music theory with Sonid, an app for iOS and Android!

Read and exercise on any device!

Why learn music theory?

Music theory backs your knowledge about solfege

Help your ears play music.

Help your ears to play the right note or chord by understanding which progressions are in a certain key. Or which scale is to be played at a given moment in your song. Make variations of what is to be expected by altering modes. Play moll-dur on the fourth grade or a dominant chord on the third.

Learn music theory and play any scale in your solo to express yourself fully.

Play beautiful melodies in any key.

Find the right notes at the right time. Build your solo up from the ground exactly how you feel it at the moment with passion and rejoice. From the most basic C major and A minor keys to church modes like G dorian or F lydian and altered scales like D mixolydian #11 your phrasing will be spot on.

Learn music theory and play any chord inversions on your instrument

Use chord substitutes and inversions.

Make your playing sound unique by using different versions of chords, or replace them altogether to give a change of colour in your voicings. Substitute Fmaj7 with Dm9 or play an inspiring Amaj9#11 instead of B7 to sound genuine and in control of your instrument.

Learn to compose better by understanding music harmonies.

Write the most compelling songs.

Composing new melodies and chord progressions will never feel the same after completing the music theory lessons. Express your emotions just the way you want them. Explore new realms of music harmonies and take your listeners on a fantastical journey.

Music theory helps to communicate with other musicians by having the right terminology at hand

Communicate with musicians.

Let your fellow musicians know what you expect from them using the correct terminology creating an open and creative environment to let your songs grow more naturally.

What do our users say?

Sam Bartrop

Brilliant app for those interested in learning music theory from the beginning! Great interface and easy to use. Would recommend!

Elmar Post

Easy to use and learn music theory with!

Maarten Wesselius

This app made learning musictheory fun and understandable for me! I've shown it to all my friends.

Victor Hensen

The app really managed to make me understand some more complex musical harmonies. Great!

Joeri de Valenca

I always had problems with understanding what I was playing but somehow this app made me see what I was missing.

Renee Jansen

A very user-friendly and motivating app, I learned a lot already!

What's new?

Community Forum Launch

A community forum to discuss anything music theory related!

Major update of our website

We have updated our website to include over 10 thousand images of chords and scales in any key!

Sonid version 2.0.0 has been released!

The update includes ear training exercises, UI tweaks and alot of enhancements and fixes!

Frequently asked questions

I already have some understanding of musical harmonies, how can I skip some lessons?

To skip classes and advance to new topics you can always click the 'Lock' icon of a certain module. Pass the test and you will unlock everything up to that point. To skip lessons within a class you can unlock a gold medal by clicking on the 'key' icon.

I only want to learn a scale or chord, where can I find it?

I don't play piano, can I still use Sonid?

Where should I start when learning about harmonies?

How important is it for me to learn music theory?

I am a complete beginner, is Sonid for me?

Why is the note A# not the same as Bb?


An extensive chord library including examples on how to construct and play nearly any chord you can think of.
View all chords
You can learn to play and construct the most basic scales or one of the very advanced worldly jazz scales, the choice is yours.
View all scales
Start your journey by learning some intervals so you can decipher harder to grasp music harmonies.
View all intervals