A musical scale is a very particular set of notes that can be used to construct melodies and chords. There are dozens of scales out there. Most scales contain anywhere from 1 (monotonic scale) to 12 notes (chromatic scale), but there are also scales using microtones.
If you are serious about understanding music theory it is a good idea to look into some of those exotic scales at some point, but if you are a beginner you should start with major and minor scales which are the basic building blocks of most music heard today.
Major scales
Each scale is has a particular footprint that makes it sound unique. This footprint is a set intervals (whole and half steps) between them.
For the major scale this footprint is as follows:
W – W – H – W – W – W – H
W stands for Whole and H for Half step.
Same series of whole and half steps is used to construct any major scale in any key. It is worth memorizing this step pattern by heart so you can easily construct scales on the fly without having to think of the actual notes.
To make this part of music theory more tangible let’s build a C major scale.
We start with note C and move a step up to D, then another step up to E, then half-step to F, and so on. We will end up with a scale that is familiar to us all:
C-D-E-F-G-A-B-C
Same procedure can be carried out starting from any of the 12 notes. Here is what it will look like:
| Scale | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
| C major | C | D | E | F | G | A | B |
| G major | G | A | B | C | D | E | F# |
| D major | D | E | F# | G | A | B | C# |
| A major | A | B | C# | D | E | F# | G# |
| E major | E | F# | G# | A | B | C# | D# |
| B major | B | C# | D# | E | F# | G# | A# |
| F# major | F# | G# | A# | B | C# | D# | E# |
| Db major | Db | Eb | F | Gb | Ab | Bb | C |
| Ab major | Ab | Bb | C | Db | Eb | F | G |
| Eb major | Eb | F | G | Ab | Bb | C | D |
| Bb major | Bb | C | D | Eb | F | G | A |
| F major | F | G | A | Bb | C | D | E |
Major scale is a basic scale in music and it is used as a starting point for any other scale, thus it is often encoded with numbers like this:
1-2-3-4-5-6-7
The numbers are modified with sharps (#) and flats(b) to produce different footprints and thus different scales.
Minor scales
There are several types of minor scales that you should be aware of: natural minor, melodic minor, and harmonic minor.
Natural minor scale
Natural minor scale (sometimes called simply minor scale) is derived from the major scale by lowering 3rd 6th and 7th intervals. It is most often described by the following formula:
1-2-b3-4-5-b6-b7
It is also known as Aeolian mode.
Here is a table of natural minor scales in all 12 keys:
| Scale | 1 | 2 | b3 | 4 | 5 | b6 | b7 |
| C minor | C | D | Eb | F | G | Ab | Bb |
| G minor | G | A | Bb | C | D | Eb | F |
| D minor | D | E | F | G | A | Bb | C |
| A minor | A | B | C | D | E | F | G |
| E minor | E | F# | G | A | B | C | D |
| B minor | B | C# | D | E | F# | G | A |
| F# minor | F# | G# | A | B | C# | D | E |
| Db minor | Db | Eb | Fb | Gb | Ab | Bbb | Cb |
| Ab minor | Ab | Bb | Cb | Db | Eb | Fb | Gb |
| Eb minor | Eb | F | Gb | Ab | Bb | Cb | Db |
| Bb minor | Bb | C | Db | Eb | F | Gb | Ab |
| F minor | F | G | Ab | Bb | C | Db | Eb |
Harmonic Minor scales
Harmonic minor scale is defined by the following formula:
1-2-b3-4-5-b6-7
Here is the table of harmonic minor scales in all 12 keys.
| Scale | 1 | 2 | b3 | 4 | 5 | b6 | 7 |
| C harmonic minor | C | D | Eb | F | G | Ab | B |
| G harmonic minor | G | A | Bb | C | D | Eb | F# |
| D harmonic minor | D | E | F | G | A | Bb | C# |
| A harmonic minor | A | B | C | D | E | F | G# |
| E harmonic minor | E | F# | G | A | B | C | D# |
| B harmonic minor | B | C# | D | E | F# | G | A# |
| F# harmonic minor | F# | G# | A | B | C# | D | E# |
| Db harmonic minor | Db | Eb | Fb | Gb | Ab | Bbb | C |
| Ab harmonic minor | Ab | Bb | Cb | Db | Eb | Fb | G |
| Eb harmonic minor | Eb | F | Gb | Ab | Bb | Cb | D |
| Bb harmonic minor | Bb | C | Db | Eb | F | Gb | A |
| F harmonic minor | F | G | Ab | Bb | C | Db | E |
Melodic minor scales
Melodic minor scale is defined by the following formula:
1-2-b3-4-5-6-7
Here are melodic minor scales with notes for all 12 keys:
| Scale | 1 | 2 | b3 | 4 | 5 | 6 | 7 |
| C melodic minor | C | D | Eb | F | G | A | B |
| G melodic minor | G | A | Bb | C | D | E | F# |
| D melodic minor | D | E | F | G | A | B | C# |
| A melodic minor | A | B | C | D | E | F# | G# |
| E melodic minor | E | F# | G | A | B | C# | D# |
| B melodic minor | B | C# | D | E | F# | G# | A# |
| F# melodic minor | F# | G# | A | B | C# | D# | E# |
| Db melodic minor | Db | Eb | Fb | Gb | Ab | Bb | C |
| Ab melodic minor | Ab | Bb | Cb | Db | Eb | F | G |
| Eb melodic minor | Eb | F | Gb | Ab | Bb | C | D |
| Bb melodic minor | Bb | C | Db | Eb | F | G | A |
| F melodic minor | F | G | Ab | Bb | C | D | E |