Musical Notes - Music Theory Concepts

If music is a language, then notes are its alphabet - the handful of building blocks everything else is made from. And it really is a small handful: Western music, the system you'll hear almost everywhere today, is built from just twelve notes. Every melody, chord and song you know is assembled from these twelve.

Press the buttons below to hear each one and watch it light up on the piano. (You can also play the on-screen keys, your computer keyboard, or a MIDI controller - the buttons light up to match.)

Seven letters, five in between

Seven of the twelve notes carry plain letter names - A, B, C, D, E, F, G. Run past G and you simply start again at A. These seven are the natural notes, and on a piano they're the white keys.

Between most of them sits a fifth note: the five accidentals, the black keys. An accidental is named relative to its neighbours with a sharp (♯, meaning raised) or a flat (♭, meaning lowered). Here's the catch that trips up beginners: the sharp of one note and the flat of the note above it are the same note - A♯ and B♭ are one pitch with two names. Notes that sound identical but are written differently are called enharmonic equivalents, which is why each black button above shows both spellings.

So which name do you use? It depends on direction. Going up in pitch we tend to spell with sharps (C, then C♯…); coming back down we spell with flats (D, then D♭…). The note is the same either way - only its written name follows the direction of travel.

You'll also notice something missing: there's no black key between B and C, or between E and F. Those pairs sit directly next to each other with nothing in between. It's a quirk of how the system grew up, and for now it's enough to remember that B-C and E-F are the close pairs.

The note circle

Because the twelve notes just keep repeating, it helps to picture them not as a line but as a circle - a clock face with the notes in place of the hours. There's no real "first" or "last" note; you can start anywhere and keep going round.

The twelve notes, ascending a half-step at each step clockwise - the direction we spell with sharps (♯). Travel counter-clockwise and the pitch falls, the direction we spell with flats (♭). Step twelve times and you arrive back where you started, one octave higher or lower. Play anything and the matching note lights up.

Distance - Tone / Semitone, Step / Half-Step

The distance from any note to its nearest neighbour - one key to the very next, black or white - is the smallest step in this system: a half-step, also called a semitone. It's exactly one piano key, or one fret on a guitar, which is why both instruments have twelve of them per octave. Two half-steps stacked together make a whole step (traditionally also called a tone) - for example C up to D, with C♯/D♭ passed through on the way.

That's the whole raw material of Western music: twelve notes, a half-step apart, repeating up and down the keyboard. Everything from here - scales, chords, keys - is a way of choosing and arranging some of these twelve.