Basic Music Theory (in under 30 minutes)

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Let's get you started with the basics of music theory - in under 30 minutes! The chapter is a condensed crash-course and suitable for low to upper beginners. 

We’re following the 80% rule: Focus on quick wins and don't bother with exceptions for now.

Understanding the fundamentals of music enables you to make conscious decisions when composing. It helps you make your music sound as you want it to, rather than being an unfortunate series of harmonic accidents.

A little music theory can go a long way. Huzzah! 

What is pitch in music?

When you hear musical tones, they sound high or low to you. This is called pitch. Pitch is determined by the sound wave frequency, measured in hertz (Hz) units. 1 Hz = 1 vibration per second. A higher frequency produces a higher pitch and vice versa.

As you can see from the image, orchestral music happens somewhere between 16 Hz and 20,000 Hz, so it can be heard. Unless you compose for elephants, of course :)

The frequency of the middle C, for example, is around 261.63 Hz. It vibrates 261.63 times per second.

Notes

Notes are the smallest unit of music. If you're building a house, you'll need bricks (at least in Europe…). You stack and arrange them to form a bigger whole. That's what you do with musical notes, too! A note is a pitch (high or low) that sounds for a specific time (note length). 

Note = pitch + duration

We've learned that notes would be written down in Hz (pitch) and seconds (duration). But that would look a bit scientific, and we don't want to use decimals numbers with comma values for writing music…

That's why music simplified things.

Note names

Pitches with specific frequencies are given note names.

Examples: 

Much easier to say, "Let's play a C, then follow up with an A," instead of "Let's play a 261.63 Hz, then 440 Hz".

Notice that notes with double the frequency have the same note name but with a higher number. C6 is double the pitch of C5. C4 is half the pitch of C5.

It's the same note but a so-called octave higher. The name octave comes from the Latin word octo for the number eight. There are 8 note steps from C4 to C5 (see table).

Note duration

The duration of a note is also simplified into note lengths. Let's take a C4 pitch and give it a duration. For example, 2 seconds. This is our full, whole note.

Half of that note would be 1 second. Two half notes have the same duration as a full note.

A quarter of the note 0.5 seconds. Two quarter notes have the same duration as a half note. 

And that's precisely how music uses notes. You define the duration of a "full note" and then work with its relatives (half, quarter, etc.). With this, we can build patterns. The human brain loves patterns. 

Much easier to say, "Let's play a quarter note, then follow up with two eight notes," instead of "Let's play the first note for 1.25 seconds, then follow up with two notes of 0.625 seconds".

Because of this organization, there are different types of musical notes. 

Notes can last for different amounts of time depending upon their type; for example, quarter notes have four beats per bar, whereas eighth notes have twice as many beats per bar. The duration of a standard note varies from song to song. This is called tempo and usually represents the duration of a quarter note.

A piece with a quarter note duration of 1s has a tempo of 60 beats per minute. A quarter note duration of 0.5s corresponds to a tempo of 120 beats per minute.

Rhythm

You create rhythm by attaching different note lengths to create a pattern of sound in time. Simply spoken.

This is an example of a rhythmic pattern. It can be clapped with your hands and doesn't require an instrument.

You might already figure out that the sequence you hear uses 2 longer notes, 2 shorter notes with twice the speed, followed by one last note. Two quarter notes, two eighth notes, and one last quarter note. The final note could also be a half or even a whole note.

A higher tempo makes the pattern sound faster but doesn't change the sequence itself.

The time signature tells you how many beats are in each bar. I said that a whole note lasts 4 quarter notes and fills one bar. This means that 4 quarter notes also fill a bar. The time signature is 4/4 (speak: four quarters). There are other time signatures, for example, 3/4. Here, 1 bar is already filled by 3 quarter notes.

Rhythm patterns can be expanded by pronouncing some notes more than others, adding small pauses, and using more complex note lengths like triplets or dotted notes. We'll keep it simple here.

That's because we use the same note (= same pitch). Let's change up the notes, but keep the rhythm.

But how did I know which notes to select, so it sounds good and not like a chaotic mess? Because I knew which intervals to choose.

Note Intervals

A note interval is the distance between two notes. You can understand note intervals with a piano keyboard.

The smallest interval in music is called a half step, or semitone. On the piano, each neighboring key is precisely one half step above or below.

The next interval is called a whole step, corresponding to two semitones.

• Half step = semitone. The same thing! 
• Whole step = 2 semitones

An interval is measured in half steps, which means there are 12 intervals per octave, just like there are 12 piano keys per octave. In a higher or lower octave, it all repeats the same way.

Let's find the perfect fifth of note C (marked in blue). According to the table, we must go up 7 semitones (piano keys). The fifth of a C is G (marked in green)! Fifth intervals sound very clear and often have a heroic or majestic emotional component when played upwards.

What about the minor third of F (marked in blue)? That's 3 semitones (piano keys) away. 1, 2, 3… A-flat (marked in green)! Minor thirds have a mellow, darker sound often interpreted as sad or melancholic.

Fun fact: The tritone (6 semitones) has been labeled the devil's interval due to its dissonant sound.

Knowing your intervals lends you the superpower to write compelling melodies.

Melody

Melodies are some of the most essential elements of music. They are usually the first thing that comes to mind when thinking of your favorite song.

A melody is a sequence of notes with varying intervals. It can be sung with the voice or played by musical instruments.

Here's an example of a famous, simple melody ("Twinkle, twinkle, little star"). It goes C-C-G-G-A-A-G.

Is it a sequence of notes? Check!

Can it be sung? Well, it's a famous lullaby. Check!

Does it have varying intervals? Let's see. It goes from C to G in a perfect fifth (7 semitones). Then, it goes from G to A in a major second (2 semitones). And ultimately, back from A to G in a major second (2 semitones).

Varying intervals: Check!

Most melodies are made up of notes from one scale.

Scales

The scale is the foundation for melody and harmony. They are note sequences, like melodies, but scales always follow a specific interval pattern.

They are like encoded instructions of half and whole steps.

There are two main types of scales: major and minor. Major sounding generally bright or happy, and minor sounding more mellow and dark. Together, the notes in a scale make up a key and overall feel of a song; based on the scale, you pick the melody notes and harmonies.

Scales usually contain 7 notes and span one octave. They always end on the same note they started with ("root note"), just one octave above.

The key of C major has the following notes: C, D, E, F, G, A, and B.

Notice how joyful and pure it sounds.

Scales are named after the first note in the scale, followed by a code name. Code names like "major" or "minor" stand for the interval pattern.

Feel free to double-check: The 7 notes of the C major scale C, D, E, F, G, A, B, and back to C are indeed spaced in a W-W-H-W-W-W-H pattern!

You can play the C major scale by starting from C and playing only the white notes on the keyboard. They are laid on in a way that the white keys follow the W-W-H-W-W-W-H pattern.

Similarly, only the white keys starting from note A result in the A minor scale (W-H-W-W-H-W-W pattern).

If both scales contain only white keys, that means that the C major and A minor scales share precisely the same notes, right? Absolutely. That's why they are called relative keys.

Relative keys go very well with each other in a song.

Remember the minor third interval (3 semitones) we built in the note intervals section earlier in the chapter? We said it sounds dark and sad. That's because the minor third interval is the most defining part of a dark-sounding minor scale.

The minor third is a whole step plus a half step (3 half steps in total) up from the root note. If you look at "W-W-H-W-W-W-H" and "W-H-W-W-H-W-W" above, which one starts with a whole step + a half step? The second one: W-H! The W-H, in the beginning, is the secret formula hidden behind the term "minor" when it comes to scales.

Modes

Modes are like slight variations of the same scale. They change the whole-step and half-step formula for a little extra flavor.

The typical Western music we hear today uses mostly Ionian ("major") and Aeolian ("minor") modes. Remember the steps? W-W-H-W-W-W-H for major, and W-H-W-W-H-W-W for minor.

But many other interesting modes spice up a scale by altering one or two steps.

Modes give us access to a world of sound that we wouldn't otherwise have access to within the major and minor scales alone.

Here's a reference list of all modes. Don't bother memorizing them for now.

(W = whole step, H = half step, WH = whole step + a half step)

Try out a few on your piano or a virtual keyboard. Start from the C and go up each mode's half and whole steps. You'll notice that they sound a bit different.

The Lydian mode, for example, often creates an "otherworldly" mood. John Locke's theme by Michael Giacchino (from my all-time-favorite TV series Lost) starts with a piano playing the Lydian scale.

Knowing your modes increases the range of moods and atmospheres you can create in your orchestral compositions.

Chords

What are chords?

Chords are groups of notes played together at the same time. We use them to create a sense of structure as we move from one section of a song to another. They can be used to create tension and release to make a piece exciting or add color and depth to an existing melody line.

The most basic chord is stacked thirds, either major or minor thirds. These chords are called triads. The C major triad is made of the notes C-E-G (major third + minor third interval), and the C minor triad of the notes C-Eb-G (minor third interval + major third). The 1 and 5 are the same between a major and minor triad.

The most frequently used chords are from the first, fourth, and fifth notes of the song's key; for the C major scale (C-D-E-F-G-A-B-C), that would be C major, F major, and G major.

Chords can be simple or complex, depending on how many notes make up each chord. Most songs use simple three-note chords like C Major or F minor. But you can add notes to a chord to change its emotional connotation and make it more nuanced. The Jazz genre is famous for its complex chords.

A chord progression is a group of chords played one after another. No other musical element has a more significant effect on a track's overall mood and atmosphere than the chord progression.

Chord voicings and inversions

Chord voicings are ways to arrange the notes of a chord across octaves. In a triad, you have the root note followed by stacked third intervals. But you could also move a third interval to the low bass range and have the root note play very high. Or remove one chord note altogether.

Each voicing of the same chord sounds unique and tells the listener a slightly different story.

Inversions are a type of chord voicing. An inversion is when you play the notes of a chord in a different order.

For example, if you play all three notes of a C major triad (C-E-G) in one octave (the original voicing), you get this:

If you play them again but move the C up like so...

...you've just played the first inversion of C major—but it still sounds like C major! It's just different from before because now E is the low note. If we move E - currently the lowest note - up an octave like this...

...that's our second inversion.

Like voicings, you can make a chord more interesting with inversions. Wherever a triad sounds bland and uninspired in your track, try changing around the notes (inversions) and space them out across the keyboard range (voicings).

Conclusion

Music theory is essential for understanding everything from pop music on the radio to the most complex classical pieces.

It also helps us understand why we like or dislike certain pieces of music.

Suppose someone hears a piece with dissonant chords, then another with consonant chords (chords that sound good together). In that case, they might prefer one over the other even though they're both composed by Mozart! Unless it's the score for a horror movie.

This is because learned preferences evolve based on exposure to certain styles over time; everyone has developed personal tastes based on their own experiences.

Much of the music you hear on the radio comprises simple melodies, harmonies, and rhythms. But there's a lot more to it than that! Music theory can help you understand how those elements work together and gain a new level of control in your compositions.

These were only the absolute fundamentals of music theory.

In this chapter, we've learned a lot. But there is much more out here to be explored, and it will take a much longer time for you to master all those more advanced concepts.

But, we are now in a place where we can writing music ourselves!

Learn more