When we talk about intervals, we are merely referring to the distance between two different pitches. It’s a fun bit of music theory that ultimately makes sense, but the problem is that people tend to learn intervals in so much as what they are that they forget to recognise the powerful context they give that can help us become a better rounded musician. Recognising intervals can massively help out all aspects of music: performing, improvising and composing, sight reading, playing by ear etc.
So let’s take the basic intervals and work them out.
In this blog, I shall be using the C major scale:
C
D
E
F
G
A
B
and finding the intervals from the root note (C) to demonstrate the different intervals.
Because we are using the C major scale, we can assume that all of our intervals from this root note will be major. This is with the exception of perfect intervals, which I shall come onto, but to give you a quick rundown:
C - D: major second
C - E: major third
C - F: perfect fourth
C - G: perfect fifth
C - A: major sixth
C - B: major seventh
C - C: perfect octave
Before I take on each of these, let’s firstly talk about the ‘impossible’ interval to play on a piano:
Unison
Unison is generally used when two or more instruments play the same pitch, such as Middle C. Alternatively, some instruments - such as bowed or some plucked string instruments like violin or guitar - can play two notes together at the same pitch as they can manipulate the pitches of two separate strings to allow them both to play.
The piano, however, is strictly one pitch per note, so you can’t play unison on piano unless either:
You tune it that way (why? Surprisingly not as uncommon as you might think amongst 20th century piano composers, but certainly not conventional!)
Much more likely, you have a second piano to double up on the pitch (such as if you and a fellow pianist are performing a duet or a “piece for four hands”).
Why is it important, then, for us as pianists to be aware of unison?
Well, it’s purely because of the way it affects how we might approach a certain passage of music and it relates back to voices. Suppose that you have an arrangement whereby you want a middle C as part of the melody but also a long middle C held on in the background of the bar. This is easy to arrange with a small ensemble, but on a piano you might have to get creative:
In the above examples, both bars are technically the same, however the first bar suggests that the middle C is purely an accompanying part. In the second bar, having two notes of the same pitch but different lengths right next to each other isn’t a print error ‘nor uncommon to see in music, but what it suggests is that the middle C quaver is as much a part of the melody as the subsequent quavers but also needs to be held on for the semibreve duration as an accompaniment. As a performer, you might just want to give a touch more emphasis on the middle C if you saw it notated as the bar on the right to allow the note to be an equal member of the melody!
Let’s now focus our attention on the individual intervals from C in the C major scale:
Major Second
C - D is our major second.
It’s worth playing intervals two ways to get used to their sounds:
Harmonically: this means to play the two notes at the same time.
Melodically: this is simply playing one note after the other.
When working through these intervals, play them all both of these ways but listen to how they sound and take note of how they are notated as well:
Note that our second is any note on the stave to the note directly above it, whether this be a line or a space.
Major Third
C - E is our major third.
Try playing the major second followed by the major third.
What you will hear in doing so is what we call ‘resolve’. Resolve is where we create a sense of incompletion in our music, but then rise it up (or lower it down) to make it sound more complete. A major second to a major third is a classic example of resolving.
On notation, we’re just shifting the distance by one space or line each time, so whilst our root note of middle C is in the same place, the second note has just raised up to the next line or space. In this case, it shifts it up to a line to reach E. Therefore, a third is separated by one whole line or space:
Introducing the Power of Written Intervals and Sight Reading
I am a big believer that the best sight readers don’t read note for note so much as they read using patterns or logic, and now you understand what a second and a third look like in notation, we can actually use these to dramatically improve our instinct.
You will have noted that when referring to notation for the second and third, I didn’t specify that the distances represented a major or a minor second.
This is where we need to bring in another aspect of our musical understand and theory: scales and key signature!
Using C major as our more basic example, we can draw up a scale of thirds and use this to exemplify our point:
Note there is no key signature, therefore we know there are no sharps or flats. This is obviously important!
Now we have established that this is in the key of C major, we can be certain that our first third on the scale makes a major third. Now, irrelevant of what types of thirds (major or minor) the others make, you can still work them out on the keyboard easily enough because of the distance between the notes in the scale.
In C major it is easy because with thirds you just leave a white note between your two notes, so find any white note, leave a white note above it and play the next white note and there is a third, so learning to identify the physical distance between notes in the scale and upping your instinct in the scale itself will benefit your sight reading greatly.
To further exemplify, here is the same thing but in the key of D major:
We can already spot that they are exactly the same intervals - all thirds - but now we have to take into account our F♯ and C♯. Once we get into this mindset, it becomes a whole lot easier to be able to work out the distances.
Perfect Fourths and Fifths
It’s important to understand why fourths and fifths are called ‘perfect' and don’t fall under the major or minor category.
The simple answer is because they both fall under the root note’s major and minor scale.
There is an exception to the rule here in as much as the second we have learnt (major second) also falls under them both because, well, it wouldn’t be music theory without a few exceptions to the rule! But more on that later...
However, the following C major scale:
C D E F G A B
and the following C natural minor scale:
C D E♭ F G A♭ B♭
Only share the F and G otherwise, aside from the root note. Therefore, a fourth or a fifth does not make a major or minor tonality, hence why we call it ‘perfect’.
Notating a fourth is as simple as taking the distance of the third we have already learnt and moving the top note up by one line or space. In the case of our third (C and E), this shifts the E up to the first space on the stave from the bottom - F. So conclusively, a fourth is three lines and spaces apart:
Try playing the perfect fourth followed by the major third. This is another example of resolve!
By shifting that F up to the line above, we create our perfect fifth. In this case, moving F up to G:
Fifths are nice and easy to spot because they create symmetry within the space. Both notes will either be on a line with one line and two spaces between, or both will be in a space with two lines and one space in the middle.
When playing perfect intervals, note how they sound a bit emptier than the two major intervals we started with. This is just on account of them being not tied to any tonality. That’s why they’re perfect!
Major Sixth and Seventh
C - A is our major sixth and C - B is our major seventh:
Play these harmonically and melodically as well and hear the difference compared to the other intervals.
Needless to say, if you take our notated fifth (C - G) and push the G up to the space above, you get our sixth:
Then, push the A up to the line above (B) and you get the seventh.
Perfect Octave
And now we reach the octave. Again, this is perfect because it doesn’t subscribe to major or minor seeing as they are just the same note, different pitches!
Despite octaves being officially ‘perfect’ and sounding nice and clean compared to a major seventh, it is worth mentioning that the notation of an octave is a little asymmetrical. If the top note is a space, the bottom note will be a line and vice versa:
It is useful to get used to this, however, because in many pieces of music you will find that you need to read octaves and passages like this:
…will be infinitely less challenging to read because you will recognise the shape of the interval and only really have to read the top notes, which are comfortably within the stave.
Minor Seconds
I suppose I’d best address my earlier point about minor seconds!
Whilst it is a major second that appears in both major and minor versions of a scale (such as C - D in both C major and C minor), if we reduce that second note by one semitone (i.e. flatten it) then we create a minor second. This creates C - D♭. A minor second is a distance of just one semitone and they appear twice in a typical scale:
Between the 3rd and 4th (E - F in C major)
Between the 7th and octave (B back to C in C major)
Which one you play depends on which key you’re in. For example, if you see E - F notated in the key of C major, it’s that. However, if you see those same two pitches notated in D major, it’s E - F♯ - thus a major second.
Intervals Within Chords
We don’t just have to recognise intervals as being two notes.
Take the following four chords as an example:
We can identify each of these chords far more quickly by choosing maybe one note or interval to start with and just using distance to work out the rest, rather than working out each note separately.
Let’s firstly acknowledge that the passage is in C major, thus no sharps or flats. Important to remember!
Note in the first chord that the top two notes are a second. Note also that the top and bottom note is a fifth.
Using this logic, we can choose either note - top or bottom - and work the rest out.
For example, F is the bottom note. One fifth up is C. The note below it is B: F - B - C.
In the second chord, you may choose to acknowledge the extreme ends of the interval, which is one octave. These are both E. The middle note is a third from the bottom: G.
The third chord has a consistent third approach, so using your understanding of how thirds appear on the C major scale, find the bottom note - A - then work up the next 3 notes - C - E - G.
For the fourth chord, you can already recognise the bottom 3 notes are thirds. Starting on G, this means that they must be B and D rising up. However, the top note appears to greater than an octave from the very bottom, so just use the top note - D - and find the interval, which is a perfect fifth. All in all, therefore, G - B - D - A.
Training Your Ear
Here are some notated examples - all transposed into the key of C major for ease - of some pieces that use each of these intervals. Have a play through and listen to the interval as you do so. Much as you should be able to identify them by now, I have marked the intervals on the score with a slur!:
Just for reference, the pieces are:
Happy Birthday
Spring (from "the Four Seasons")
La Cucharacha
Can't Help Falling In Love
My Bonnie Lies Over The Ocean
Take On Me
Over the Rainbow
Conclusion: Learning Intervals on Piano
It has to be said that learning intervals is an incredibly useful tool as they will massively help you pick out parts of melodies and harmonies - thus developing your ear - as well as helping your sight reading, which I hope I have started you on your way to doing above.
For my video recap watch below:
Be sure to subscribe to my YouTube channel to never miss a video like this!
Jack Mitchell Smith is a piano teacher based in Macclesfield, Cheshire. Click here to find out more.
Weekly blogs are posted that may help you with your musical or piano journey. Click here to sign up to the mailing list so you never miss a post!