This post is one of a 2-part series of free basic music theory lessons on my blog, musictheoryde-mystified.com. You can see the complete list here. Please feel welcome to make a comment or ask a question.
If you’re looking for the quick answer, scroll down to the summary.
A scale is both a sequence of note pitches you can play by itself as a simple melody (usually for practice) and the basis of a piece of music.
In 1 Note Names, Semitones and Octaves, we saw that there are 12 different musical note pitches within an octave, each 1 semitone apart. We also saw that there are only 7 letters used to name music. On a musical stave there are also only 7 pitch positions per octave, one for each letter.
This is because most music in Western culture is usually made up using only 7 of the 12 notes at a time, the eighth note being the octave (hence the name “octave”). Such a selection of notes is called a scale. The first note of a scale is the reference note for music written in that scale.
Note: It is possible for a scale to have more or less than 7 notes (such as the 5-note pentatonic blues scale) but the vast majority of music in Western culture, both historically and in modern times, is based on 7-note (heptatonic) scales.
How Far Apart Are Scale Notes?
For 7 notes to make up an octave (12 semitones), the notes can’t all be spaced evenly. Most of the notes are 2 semitones apart, but there are two pairs which are only 1 semitone apart. For example, let’s look at the naturals; the notes that have just a letter as their name.
C major
Although the notes are named starting on A, C is the starting point for the most common scale of all, C major. We’ll talk about major and minor shortly, but for now, let’s look at the notes starting on C.
C major is made up of the naturals starting on C. We can see that C to D is 2 semitones, as is D to E, then E to F is only 1 semitone, etc. This is quite easy to see on a piano keyboard, as the named notes are the white keys and the others, the black keys. The interval from one key to the next is 1 semitone, whether between adjacent white keys or between a white key and an adjacent black key. (The staggered layout of a piano’s keys is for practical reasons- so one hand can span an octave).
Note: In scales, the intervals marked as 2 semitones are usually called a “tone” rather than “2 semitones”. Other schools use the terms ”steps” and ”half-steps” for the 2- and 1-semitone intervals between the notes of a scale.
In this blog I will always name intervals by semitones or by their musical interval name. For my reasons, see A Story Of Tones And Semitones.
The Root Note
When we play a scale, we usually emphasise the first and last note, in this case, C, by playing those notes louder, longer or both. Playing a scale in this way helps us feel that the starting/ending note is the home note and that the other notes either lead away from that note or towards it.
The first note of a scale is called the root note or tonic and it is the most important note in a scale. The root note represents home in a musical journey and the start of the pattern of intervals from note to note that defines the scale.
Modes
Let’s play a scale using only the naturals, from C to C and back.
Now let’s play the same notes but starting on a different root note, such as A. We’ll play A to A and back.
Sure, one was slightly higher than the other, but did you notice a difference in character/flavour/mood? Have another listen…
… (I’ll wait)…
This difference in character is even more noticeable in a real piece than just a scale.
Now let’s compare the spacing of the notes.
Notice the difference in the order of the 2’s and 1’s in relation to the root note? It is this pattern that determines the scale’s character.
The pattern of intervals that determine the note spacing of a scale is called a mode. When using just the naturals, each time we start on a different note, the pattern of note spacing is different. There are 7 different naturals, each of which is the root note of a mode. Of the 7 modes produced, six are quite common in various genres and one, the one starting on B, is seldom used (but that’s the subject of another post).
Earlier on, I called the first scale, starting on C, C major. The term major refers to the mode. Major is the most commonly used mode in modern Western music, hence the name. The one on A is called A natural minor or just A minor for short. Minor scales are usually used in a slightly different way to major in that there are two popular variations on the natural minor. We’ll look at how these variations are used in part 2 of this course so for now we’ll use the natural minor as our minor example.
The major and natural minor modes are also known by Greek names based on modes in the renaissance era.
Major = Ionian mode. Natural minor = Aeolian mode.
What About Keys?
You’re more likely to hear people talk in terms of keys rather than scales and modes. A key is simply the notes of a scale when they are rearranged to make music.
For instance, any music which is based on the scale of C major is in the key of C major.
The major or minor (or any mode, for that matter) can be made to start on any root note. The major mode on D is called D major. The minor mode on F is called F minor. We’ll look at how this works in coming posts..
Scales and melodies
We can tell the difference between C major and A minor when we play the scale because we’re emphasising the root note – by playing it first, last and longer than the other notes. Furthermore we can hear the progression of ascending or descending notes arrive on the root note. But how can we recognise the mode when the notes are all mixed up in a melody?
It’s all about being able to recognise the root note.
Melodies rely on a range of techniques to highlight the root note including those I’ve just mentioned. A melody isn’t a random selection of notes. The structure of the phrases that make up a melody and the relative length and strength of notes all contribute to our ability to recognise the root note as home. Some of these techniques are mentioned in a little more detail in How Can We Tell Which Key We’re In?
Summary
- A scale is a selection of (usually 7) pitches within an octave, which form the basic pitch elements of a piece. The notes can be played at any octave.
- The root note or tonic is the first note of the scale and the reference/ home note for music written using that scale.
- The interval spacing of the notes of a scale is called a mode. The most common modes are called major and minor.
- Each mode imparts a unique character to the music because of its unique combination of 1 and 2 semitone intervals from note to note.
- We can hear the character of the mode because the music is written in such a way as to highlight the root note. For some examples, visit How Can We Tell Which Key We’re In?
This post is one of a growing series of free basic music theory lessons on my blog, musictheoryde-mystified.com. You can see the complete list here.
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Much of the content is based on my upcoming music theory reference, Music Theory De-mystified, which is currently planned for release as an e-book by the end of 2023.
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PART 1 CONTENTS: Basic Music Theory Course Contents