Music Lessons Tips: How Intervals Work
Updated: Mar 15
Intervals (The distance between notation) is crucial for understanding all multitudes of the music world. More specifically learning their proper names and their function.
In this blog I will help you understand all interval names between all musical notes but also within the confines of the Major Scale.
If you're new to notes in music and want to first understand how they work, I suggest you read my blog about that before diving in to this.
Let's start with the musical note names.
The biggest obstacle in learning the note names is the language barrier. There are two prominent ways to name notes.
Using the Latin Alphabet, and using the Italian/Greek origin of notation or "Solfège'".
There are some other methods out there, but we will focus on those two as in most countries you will find either of the two.
In the Latin Alphabet, notations are assigned a letter from A to G (plus the addition of accidentals i.e. Sharps & Flats). In the origin of Italian/Greek (or Solfège) we use specific names of each note (also 7 in total).
Let's have a look at how there equate on to the other. We'll start with A in English as most people understand that more easily:
A B C D E F G
La Si Do Re Mi Fa Sol
Notice I've written them down without accidentals (Sharps & Flats, Diez & Bemol). That is because as you might already know adding accidentals don't change the letter or note name we use but simply adds the sign of the accidentals (# / b).
Here is a chart that does show the differences between the two methods with accidentals.
This time starting on C / Do:
Now that we have all the names down, let's look at the distances between them.
As you know the smallest distance we can create in (Western) music is called a semi-tone or a half step. this the equivalent of counting number using halves. (0 0.5 1 1.5 2 etc.).
However in music we do start with naming distances where there's also no distance between notes i.e. the distance between A and the same A (which is 0 distance). The reason for that is due to the fact that music in mostly written for more than one instrument and we often times want several instruments to play the same note and so we need to name that distance too.
So, that said, let us chart down all the distances names. I will divide the chart into two parts; the Latin Alphabet and the second of the Solfège.
Note that the Solfège names vary between languages and online you will mostly find the English version of the intervals.
*Note that there also names for distances above an octave, but they are less commonly used.
These distance names are used in various ways but, the most common way to use them is to determine the structure of a scale or a chord. To understand quickly how it is constructed, how it works and how to use it.
More importantly each interval carries a tone, a color or emotion with it and by revising them you can learn how to use them, compose and identify them more easily.
The unison is the most boring interval of all: it happens when two notes are exactly the same, such as C on top of C. For this reason there isn’t much we can do with it. No melody, no harmony. No major, no minor, nothing indeed. A unison interval just is.
The unison is a consonance (the most perfect there is!) and, obviously, a stable interval.
The first interval we have is called the 2nd. Start from any note, the 2nd will be the first note after that. A to B, E to F, A to G, and do so on. Because seconds are the shortest interval between two notes, they are the most common intervals used in melodies and often referred to as passing notes (or passing tones). If you go from C to E without skipping any notes, you'll pass by D on the way.
An interval of a 2nd sounds quite harsh, therefore it is not stable and we consider it to be a dissonance.
That means that whenever you hear an interval of a 2nd played together you should expect it to be “resolved” down. After that interval you expect to hear the C alone, so C and D together would resolve with the D “falling” onto the C.
Minor 2nd = 1 semi-tone
Major 2nd = 2 semi-tones
A minor 2nd will create the strongest tension (therefore strongest attraction to the unison) because it sounds even more dissonant that the major 2nd.
Here is an example of music that takes great advantage of the tension created by a minor 2nd (turn up your volume):
Thirds are some of the most common intervals we see in western music! Many country songs are “harmonized” by a second singer. Harmonizing a melody simply means copying it a 3rd above and singing both lines together. Chords are 2 thirds stacked on top of each other, such as in the C major chord (C – E – G): C to E is a 3rd and E to G is another 3rd.
The 3rd doesn't create any tension, so it is considered a stable and consonant interval.
Minor 3nd = 3 semi-tones
Major 3nd = 4 semi-tones
Listen below to how the right hand uses thirds extensively in this famous piano piece. The melody you hear is actually being played with two notes together, a 3rd apart.
The 4th and 5th
Remember from the beginning of this post how the 4th and 5th are special intervals? Well, here we go. Both the 4th and 5th chords in a given key, together with the first one, form the foundation for music harmony. In short, all chords in a key “gravitate” around their tonal center (the first chord, known as the tonic). That attraction depends on the immutable presence of the 4th and the 5th. Change one of them, and the music will stop making any sense because it will lose its main structure.
The immutability of both is so crucial for music harmony that we refer to their natural state as Perfect. The interval of a 5th in its normal state in any key is called a perfect 5th. The same is true for the 4th.
Needless to say that both perfect 4th and perfect 5th are stable and consonant intervals. They are points of resolution and central to our notion of tonality. They may be, however, altered for the sake of dissonance. In that case, those changes will create dissonances that must be immediately resolved. Why do they have to be resolved? There are no keys where the 4th or 5th chords are not perfect. If, for example, the 5th chord in a key is repeatedly played in its augmented form, this music will soon stop making sense and its relationship with the tonic chord will be diluted. If we lower or raise those intervals one step down or one up, we create the following intervals:
Diminished 4th = 4 semi-tones (dissonant)
Perfect 4th = 5 semi-tones
Augmented 4th = 6 semi-tones (dissonant)
Diminished 5th = 6 semi-tones (dissonant)
Perfect 5th = 7 semi-tones
Augmented 5th = 8 semi-tones (dissonant)
Let's see an example of a perfect 5th in the movies!
The opening notes in this theme are perfect fifths. In fact this interval is part of the theme in this music and we hear it all over the place.
The Devil's Interval
Let's take a quick break to talk a little bit about a very important and, at one time, controversial interval. The augmented 4th is the most dissonant interval of all. It is so harsh and bizarre that it has its own nickname: the tritone. A tritone creates an incredible tension when played together, listen to how Camille Saint-Saëns used the tritone to create a bizarre, evil like theme in this piece
Hear that harsh sound from the violin at second 18? That is what the tritone sounds like. During the middle ages this interval was prohibited by the Catholic Church. Composers and theorists at the time considered music to be a direct representation of the image and world of God and thus, the tritone with its harsh and ugly sound was something from the Devil. That is also where the nickname comes from.
Today the tritone is fundamental to our notion of a tonal center in any key precisely due to its incredible tension and instability. The tritone always "resolves" (aka the movement to a consonant interval) into the tonic of the key. It can resolve outwards, where the top note moves one step up and the lower note moves a step down. Or it can resolve inwards, where the top note moves down one step and the lower note moves up a step.
Play a tritone, then move both notes outwards, like on the image below.
Much like the 3rd, the 6th is a consonant interval. Bring a 6th one octave below and you’ll have a 3rd: C to A is an interval of a 6th, while A to C is an interval of a 3rd. For that reason much of the characteristics of the 3rd are shared by the 6th.
It is a stable and consonant interval, often used to resolve the dissonance created by the tritone.
Minor 6th = 8 semi-tones
Major 6th = 9 semi-tones
Listen below to an example of a 6th being used as an opening to a theme. The first two notes are a major 6th apart.
The interval of a 7th, much like all other intervals (except for the 4th and 5th), can be major or minor. The major 7th has one special name: we call it the leading tone. The reason for that is because the major 7th, sits just one semi-tone before the 8th, which is the tonic (the first note note repeated an octave up). Being so close to the tonic, it creates the greatest attraction to the it and our ears almost beg to hear that tonic after a major 7th. When we hear the 7th of a scale together with the 4th it creates the tritone. The tension created by that interval combined with the presence of the leading tone makes our ears anticipate the resolution even before we hear it.
The 7th is unstable and dissonant, and it is often used together with the 4th to create the tritone.
Minor 7th = 10 semi-tones
Major 7th = 11 semi-tones
Beethoven knew this very well and played with this idea in his first symphony. Listen to the first 23 seconds in the example below:
Before the music even begins, Beethoven tricks the audience by establishing three different tonalities. In this example we hear three different tritones followed by their resolutions. Each of these new chords can be the key of the piece and it is only on the third one that we understand where the music is actually going. Beethoven seems to be searching for the "right key" until the third tritone. Then he repeats that one 3 times (probably not a coincidence we see so many 3 everywhere, but that is a topic for a different discussion) as if he was saying: here it is, I found the key I was looking for!
Let's first have a look at how intervals function within a Major scale (the most commonly used scale apart from the Minor).
A scale is a collection of notes arranged in a specific order based on a formula. This formula is based of course on intervals.
The major scale formula is as follows. We start on any note we wish and move in the following distances;
1 tone (M2), 1 tone (M2), Semi tone (m2), 1 tone (M2), 1 tone (M2),1 tone (M2), Semi tone (m2)
In a more visual way:
X 1 X 1 X 0.5 X 1 X 1 X 1 X 0.5 X
So for example, if we would like to build the major scale of C. We would result with the notes:
C D E F G A B C
(The distances between them are the same as the formula above)
Notice that on scales we always indicate that we've finished a full octave by returning to the original note name (C at the start and C at the end in this case).
To learn more about how scales work visit this blog post.
For more guitar tips visit my other Music Lessons Tips blogs. For Music Lessons you, may contact me directly.
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