A sound is a wave.
Every sound is created from vibrations in the air.
Music theory, made playable
A little theory.
A lot more
possibility.
Make sense of the music in your head. Learn to build chords, write melodies, and find your way around the keys.
Start free. No instrument or experience needed.
Your first soundSound on
Move a little.
Hear a difference.
Hold and drag the dot to change the sound.
For curious ears
and bedroom producers.
48 interactive lessons
9 chapters to explore
Try your first lessonWhy learn basic music theory?
Do you want to be able to make your own music, build your own chord progressions, or even improvise your own melodies? Do you want to skip all the jargon and complicated symbols?
With this course, you'll learn basic music theory the simple way with bite-sized lessons, no confusing notation, and no instruments required!
Your keyboard for today. Click a key to hear it.
Sound. What is it?
It can be louder...
Increasing the height of the wave, or amplitude.
...or more quiet.
Decreasing the height of the wave, or amplitude.
It can be lower in pitch...
Lower notes will become longer waves.
...or higher.
And higher pitched notes will be more compressed.
There are infinitely many notes.
Not just the ones you know, like A through G, but everything in between. So how do we pick which notes to use?
Harmony
Notes that sound good together.
What makes this sound good?
...and this sound bad?
A simple ratio between the notes means they sound nice together.
Can you see the repeating pattern in the first one? Your ears can hear the simple ratio between these waves.
It turns out that when the waves line up in nice patterns, it sounds good!!! Our ears like it when the ratio between the waves are simple.
For example, three waves of note #1 for every two waves of note #2 is a 3:2 ratio. Now try it for yourself.
The Pentatonic Scale
The five-note system that can do no wrong.
A lot of music theory is about limiting which notes to use in your song to a small set that sound good together. The earliest set of such notes was called the Pentatonic Scale. It has five notes and looks like this:
Click the circles to play the notes.
Note 1
Lets look at each of these notes and their waveforms.
One of the most important things to understand is that the notes themselves aren't important. You could start the pentatonic scale on any frequency. In this case, Note 1 has a frequency of 200Hz, but it could be any other number as well.
What is important is the ratio the other notes have with Note 1. Lets take a look.
Note 4
For Note 4 we have a very simple ratio of 3:2. That is, for every two waves of Note 1 (200Hz) there are three of Note 4 (300Hz). Click play to hear how nice they sound together.
Note 3
The next ratio used is 5:4. Note 3 has a frequency of 250Hz. You can see that for every four waves of Note 1 there are five of the Note 3.
Note 5
The next ratio used is 5:3 to give us 333.3Hz. You can see that for every three waves of Note 1 there are five of Note 5.
Note 2
Lastly is Note 2 with a ratio of 9:8 (225Hz). You can see that for every eight of Note 1 there are nine of Note 2.
You might have noticed that this ratio isn't as simple and therefore these two notes don't sound as nice together as some of the previous notes.
Octaves
Finally, lets find a pair of notes with the simplest ratio, 2:1. This is known as an Octave and is not considered a new note. An Octave is the same note with a higher pitch. In this case 400Hz and 200Hz.
The Chromatic Scale
The Pentatonic Scale that we just covered is very limited. The notes don't have consistently spaced ratios and there are so few of them. Modern music demands a more flexible system (with more notes!)
Thus the Chromatic Scale was invented. This system added 7 more notes to fill in the gaps (with equally spaced ratios) while still including all the notes from the Pentatonic Scale.
Click each number to play the notes of the Chromatic Scale.
Almost all modern instruments are built to this system, including guitars, keyboards, woodwinds, etc. For example, see how the keys of the piano below match up to the 12-note system.
Naming the Notes
At this point we've only been labeling the notes 1 through 12. It's time to show you their real names.
Unfortunately, I truly believe that the naming of the notes is why music theory is so difficult. If I could go back in time, I would not name the notes this way. But since it's what we've been using for thousands of years, there's no real way around it. Here they are:
Let's point out some poor qualities about this:
- We use 7 letters to describe 12 notes.
- There are sharps (#) each of which can also be called a flat (♭).
- Not all the notes have sharps or flats.
- The natural letters will play a C Major scale, but only when you start on C.
Equal Temperament
This 12-note system has a lot of nice properties. The first is Equal Temperament. This means that the interval between any two adjacent notes is exactly the same.
Why is this useful? Well it means we can start a melody on any note.
Too many notes
A downside to having all of these notes is that not all of them sound good together, making this system less forgiving than the Pentatonic Scale. Lets listen to some that don't sound so nice.
Chords
Notes played together.
Here we'll take a look at two of the most common chords: Major and Minor. These are both known as Triads: simply a chord with three notes.
Build a major chord
A major triad starts on a root note. Move up 4 half steps for the second note, then 3 more for the third. Try building one on the keyboard.
Turn major into minor
Keep the root and the top note. Lower only the middle note by one half step to turn a major triad into a minor triad. Listen to how that one change affects the chord.
Keys
A group of notes used in a song.
Because not all of the 12 notes sound good together, we must select a set of notes to use in a song. This is a Key.
When a song says that it is in the key of C Major or D Minor this is simply telling you which of the 12 notes are used in this song.
That's it.
There are many different Keys but we'll cover two of the most common ones here: Major and Minor Keys. (Although similarly named, they are completely different than Major and Minor Chords.)
Major Key
Seven notes from the Chromatic Scale. The 1st, 3rd, 5th, 6th, 8th, 10th, and 12th intervals. It then repeats back from 1. This is one of the most common keys in music. Click the notes to play them.
Remember, the frequency of the starting note doesn't matter. The Major scale will always have these intervals.
Minor Key
Again, seven notes from the Chromatic Scale. The 1st, 3rd, 4th, 6th, 8th, 9th, and 11th intervals. It then repeats back from 1. This is also a very common Key.
There are many other keys, but these two are the most common. We'll save the other keys for a later lesson.
The Key Tool
Here's a little tool to help you find the notes in any Key. Notice how the pattern never changes. Instead we just shift where we begin our Key pattern.
Diatonic Chords
Chords that fit in a particular Key.
So far we've learned that:
- a Key is a collection of notes used in a song
- a Chord is a set of notes played together
- Major and Minor chords have different spacing between their notes.
A key gives us seven notes, and we can start a chord on any of them. The chord type that keeps all three notes in the key changes with the starting note.
The chords that fit in a particular Key are called Diatonic Chords.
Music can also use chords with notes outside the key. Here, we are finding the chords made entirely from its seven notes.
Which chords fit into the Key of C Major?
For each starting note from C to A, choose the major or minor chord that fits C Major. Click a choice to hear the chord and see its notes on the piano.
All three notes must be in C Major. A red × marks a note outside the key. Find the right chord to move automatically to the next starting note.
Rhythm
Sounds arranged in time.
Rhythm is the pattern of sounds and silences in music. You can hear it in a melody even when there are no drums.
A repeated pattern gives us something to follow. Change that pattern, and the same melody can feel completely different.
Make your own beat
Build a beat one layer at a time. Follow the highlighted squares, then make the hi-hat pattern your own.
Keep going
That was the beginning.
Take the next step with notes, chords, melodies, and rhythm.
Explore the courseThe full course
Follow your ears.
Build your understanding.
Start with a single sound. Work your way to the chords, melodies, and rhythms of your own music.
Coming soon
Keep learning.
Keep making music.
The full course is still in development. Leave your email if you’d like to keep learning. I’ll let you know when it’s ready.
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