Learn music theory with Sonid app icon
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Learn music theory with Sonid app icon


an app to learn and practice music theory in a fun and structured manner!

Exercise music theory on any device!

Why learn music theory?

Music theory backs your knowledge about solfège

Help your ears play music

Help your ears to play the right notes and chords by understanding which progressions are in a certain key. Use ear training to know which scale is to be played at a given moment in your song. Make variations of what is to be expected by altering modes. Know when to 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 fully express yourself

Play beautiful melodies in any key

Find the right notes at the right time. Build your solo from the ground up and be able to express yourself with passion and rejoice. Use the most basic C major and A minor keys, church modes like G dorian or F lydian and altered scales like D mixolydian #11 to make your phrasing 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. Explore new realms of music harmonies and take your listeners on a fantastic 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. This way you will create an open and creative environment to let your songs grow more naturally.

What do our users say?

Maarten Wesselius

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

Elmar Post

Easy to use and learn music theory with!

Sam Bartrop

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

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!


Frequently Asked Questions

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

What's new?

Use Sonid in spanish!

Your favourite app to learn music theory has now been translated to spanish.

Help translate Sonid

From now on you can use Sonid in your own language!

Community Forum Launch

A community forum to discuss anything music theory related!

Read all



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