The Harmonic Series
Quoted from a resource by musician Cathy Neff
Level; Intermediate to Advanced
Just like the colours of a rainbow combine to make white light, the notes in a harmonic series combine to make what we hear as a single pitch.
If you want to learn about the harmonic series, overtones, perfect, major, and minor intervals, fundamentals and harmonics, then keep reading and follow the steps below...
Keep in mind that there is lots of science involved in understanding these parts of music so don't worry if you don't get it straight away!
The Harmonic Series
There is an amazing phenomenon in nature called colour, and it is made up of light waves that we see with our eyes. Did you know that what our eyes see as the colour 'white' is actually the presence of all colours combined, and what our eyes see as the colour 'black' is actually the absence of all colour?
When white light is focused through a prism (a special see through shape), the prism acts as a filter and splits all of the colours back into separate colours, and it looks like a rainbow! The prism doesn't create the different colours; it just lets us see the colours that are already there, combined to make white light...
Music acts much the same way as colour, but instead of light waves that we see with our eyes, music has sound waves that we hear with our ears.
Instruments vibrate to create these sound waves that we call music. Instead of 'colours,' we have 'pitches'.
Just as white light can be separated into all the separate colours that go into it, a pitch can be separated into all the separate notes that mix together to make up that one pitch.
When we hear a pitch, we aren't actually hearing one pitch but a series of notes that combine to make that pitch.
This is what we call the pitch's harmonic series. Hearing all the notes in a harmonic series combined as one pitch is similar to seeing all the colours of the rainbow combined as white light...
Fundamentals and Overtones
What are they?
Did you know that our eyes are naturally drawn to certain colours?
Similarly, our ears are naturally drawn to the lowest note of the harmonic series, and this is the pitch that we hear.
This pitch is called the fundamental.
All of the notes that make up the harmonic series above that pitch are called overtones because they happen above, or 'over,' the fundamental, lowest pitch.
They can also be called partials because they are parts of a pitch.
The more common of these overtones are called harmonics, and they are frequently played by certain instruments such as harps and guitars.
If we relate this harmonic series back to colour, the fundamental would be the 'white light' (the colour we see) and the overtones would be the 'rainbow' of individual colours that make combine to make white light!
The colours of the rainbow always appear in the same order: red, orange, yellow, green, blue, indigo, and violet.
Likewise, the notes of the harmonic series always go in the same order of intervals, too!
An interval is the distance between two notes (you can pop over to our interval page to learn all about them!).
The intervals in the harmonic series occur in order of strongest to weakest intervals.
The strongest interval in music is the OCTAVE. If you were to play middle C on the piano, the octave above that would be the C above middle C.
Can you find an Octave on your instrument?
The second strongest interval is a FIFTH. A fifth above C would be G.
Can you find a 5th on your instrument?
All of these very strong intervals are called PERFECT intervals, and they are so strong that they are easily recognisable to the human ear.
I'm sure that once you had listened a few times to fifths and octaves you could pick them out - why not test yourself? Ask a friend or family member to swap between playing octaves and 5ths and see if you can pick them out!
You could liken perfect intervals to primary colours; red, yellow, and blue. They are really easy to spot and name!
The third strongest interval is the interval of a FOURTH.
A fourth above C would be F.
Can you find a 4th on your instrument?
Phew! Got your head around those intervals? Good, because octaves, fifth and fourth all occur in the harmonic series!
Major and Minor Intervals
There are intervals that occur in the harmonic series that are not as strong as the perfect intervals.
If we imagine them as colour they would be similar to the secondary colours of orange, green, and violet which are not as strong as the primary colours.
These intervals include major and minor intervals and appear in this order of strong to weak:
Major third (A major third above C is E)
Minor third (A minor third above C would be E-flat)
Major second (A major second above C would be D)
Minor second (A minor second above C would be D-flat)
These all appear in the harmonic series, too!
The Harmonic Series
What notes are in the harmonic series?
The rainbow's colours are in the same order every time just like the intervals in the harmonic series are in the same order every time!
As an example, let's look at the harmonic series of the pitch 'C' two octaves below middle C.
Notice the pattern of intervals from one note to the next.
This pattern of intervals remains the same for the harmonic series no matter which note you choose as the starting point! Easy enough to remember right?
The intervals in the harmonic series are in this order:
Perfect 8th (octave), Perfect 5th, Perfect 4th, Major 3rd, Minor 3rd, Minor 3rd, Major 2nd, Major 2nd, Major 2nd, Major 2nd, Minor 2nd, Major 2nd, Minor 2nd, Minor 2nd, Minor 2nd...
Phew - that's a lot of overtones!
Can you play all the intervals of the overtones of C on your instrument? Follow the score or count the intervals!
You just played the harmonic series!
Now, it may take a while to get your head round it but now, no matter what you play, you will know that you are always hearing all of the notes in the harmonic series when you are playing and how every note you play is a rainbow of sounds...