Intervals 1 (Semitones)
The “distance” between any two notes is called an interval. A semitone is the smallest interval possible on the piano and most western instruments. (Another “name” for a semitone is a minor second interval). When you press any key on the piano then the key that is right next to it either to the right or the left side (can be either black or white) will always be a semitone away. There are 12 semitones within an octave. In practice this means that we can play at the maximum 12 unique notes before we repeat any note (in a different register). A semitone is also called a half tone. Two semitones are are called also called a whole tone.
Intervals 2 (1-8)
There are other intervals besides a semitone. In fact there are 12 unique intervals within any octave range – the same number as there are semitones and unique notes. Intervals are referenced to a specific note so an interval is the “distance” between that note and another note. For example if we start on C (and give it a number – “1”) each interval is now referenced to that C note. We can name the intervals in several ways. The chart below shows the most common ways of naming intervals – using intervals and semitones.
Intervals are named using specific methods. Some are more common within classical education and some are more common within jazz/contemporary education. Classically and “traditionally” they are named by adding a prefix (minor, major, perfect) to an ordinal number (2nd, 4th, 7th etc.) with some exceptions. The exceptions are the (perfect) unison (1),the (perfect) octave (8) and the tritone (#4/b5). Here are some examples: minor 3rd, major 6th, perfect 4th, major 7th, tritone, (perfect) unison, (perfect) octave.
In jazz/contemporary music a simpler version of a number with an accidental is used instead. The numbers are all relative to the major scale of the reference key. If an interval is a minor a simple b is put in front. The examples above would look like this : b3, 6, 4, 7, #4, 1, 8. As you can see it is much easier and clearer. That is the method we are going to use throughout the lessons for the most part but still will use some “traditional” interval language for some topics. I call this the numeric pattern. More on this later.
This might seem very confusing in text form. In order to not overcomplicate things I have provided a table with the information regarding intervals within an octave range (1-8). The reference note is C. (All other notes are related to that one. I have put abbreviations in brackets.) Below the table is an illustration on the subject.
| Note | “Traditional” | Numeric Pattern | Semitones From C |
| C | Perfect Unison (P1) | 1 | 0 |
| D#/Db | Minor 2nd (m2) | #1/b2 | 1 |
| D | Major 2nd (M2) | 2 | 2 |
| D#/Eb | Minor 3rd (m3) | #3/b3 | 3 |
| E | Major 3rd (M3) | 3 | 4 |
| F | Perfect 4th (P4) | 4 | 5 |
| F#/Gb | Tritone (TT) | #4/b5 | 6 |
| G | Perfect 5th (P5) | 5 | 7 |
| G#/Ab | Minor 6th (m6) | #5/b6 | 8 |
| A | Major 6th (M6) | 6 | 9 |
| A#/Bb | Minor 7th (m7) | b7* | 10 |
| B | Major 7th (M7) | 7 | 11 |
| C | Perfect Octave (P8) | 8 | 12 |
*#6 is not used in jazz/contemporary notation
Intervals 3 (8-)
The previous pare covered intervals within an octave range. In jazz/contemporary music intervals over an octave (8) are used especially with chords and voicings (how a chord is spread out). In theory we cover two octaves (1-15) but in practice we only use the following numbers from the second octave 9, (10 sometimes in voicings), 11 and 13. we can notice that they each have a lower octave equivalent : 2, (3), 4 and 6. The 9,11 and 13 are called extension notes and we cover them in Chapter 2. Below is a table of the intervals used over one octave. Here the accidentals refer to a specific choice so there is only one option. (For example there is only a Db=b9 and no C#=#8 option). The octave (8) and quindicecime (15) are added for reference.
| Note | Numeric Pattern | Semitones From C |
| C | 1 | 0 |
| C | 8 | 12 |
| Db | b9 | 13 |
| D | 9 | 14 |
| D# | #9 | 15 |
| F | 11 | 17 |
| F# | #11 | 18 |
| Ab | b13 | 20 |
| A | 13 | 21 |
| C | 15 | 24 |
(c) 2019 Sibil Yanev
