Notes, octaves and intervals

Before fumbling around with chords and scales, let’s get a grip on the stuff they’re made up of: notes and intervals. There are only 12 different notes, and they repeat all the way up the piano keyboard (or piano roll). The piano is easy to visualise, with one key per note, but music theory principles work the same for every instrument.

Whichever note you start on, if you go up 12 notes from there, you’re back where you started, playing the same note, but one ‘ octave’ higher – it sounds the same but higher pitched. In addition, the pitch difference between adjacent notes is always the same, called a ‘ semitone’ (also known as a half-tone or minor second). A difference in pitch between two notes is called an ‘ interval’ – so far we’ve covered only two intervals: the octave and the semitone.

It all begins with a C

C#, D#, F#, G#, The 12 notes are named C, D, E, F, G,

A# A, and B. After that, the sequence starts over at C, as we’ve reached the octave point. ‘#’ means ‘ sharp’ and is essentially shorthand for

A# ‘plus 1 semitone’, telling us that is the note immediately above A, for example. Notes with no sharp symbol –C, D, E, F, G, A, B – are called ‘natural’ notes and are the white keys on a

C#, D#, F#, G# A#. piano. The black keys are and Notice that B/C and E/F have no sharp note between them. Also, C (rather than A) is considered the ‘default’ or ‘first’ note in music theory, not A.

Some notes lead a shady double life, as the five sharp notes can also be described as ‘ flat’, the symbol for which is ‘b’, meaning ‘minus 1

A# Bb, semitone’. So can be called for example – same note, different name! The full run using

Db, Eb, Fb, Ab, Bb, flats would be: C, D, E, F, G, A, B.

If you’re finding it hard to take in, just get comfortable with the sharp naming scheme first. Most music software uses only sharps anyway, so to make sure our tutorials translate to your software, we’re going to use sharps pretty much throughout (even where they might be considered ‘wrong’ in traditional music theory).

Let’s go after the interval

It’s time to look at the other intervals – we’ve put a table of the intervals (from 0 to 12) over on the right-hand side of the page.

Notes played one after the other make a ‘melodic interval’, and no matter which of the notes you play first, it’s the same interval – we’d just call it ascending or descending. When the notes are played at the same time, that’s a ‘harmonic interval’.

Each interval has its own sound. The ‘ unison’ and ‘ octave’ intervals sound very clear, since they’re playing the exact same note – no surprise. However, the next clearest are the 7and 5- semitone intervals, known as a ‘ perfect fifth’ and a ‘ perfect fourth’ – the reason for this naming will become clear soon, we promise!

Next, the 4- and 3-semitone intervals – named ‘ major third’ and ‘ minor third’ – also sound musically satisfying, with a ‘happy’ and ‘sad’ feel respectively. Memorising each interval and being able to identify them by ear will help massively in making music, and a common trick to help with this is to associate each interval with the opening notes of a well-known tune. For more, see bit.ly/IntervalIdeas.

“Memorising each interval and being able to identify them will help massively”