Sharps and flats (♯ and ♭) and enharmonics

Twelve tones, not seven

The musical alphabet has seven letters, but between most of them sits one more tone. We reach those in-between tones with sharps and flats. Together this gives us twelve tones that repeat in a cycle - the chromatic scale.

A semitone is the smallest step

The smallest distance between two tones is a semitone (one fret on a guitar). Two semitones make a whole tone. Every scale is built from these two steps.

• Sharp (♯) raises a tone by one semitone: C♯ is one fret higher than C.
• Flat (♭) lowers a tone by one semitone: D♭ is one fret lower than D.

Enharmonics: one sound, two names

Because C♯ is a semitone above C and D♭ is a semitone below D, they are the same tone - just two names for one sound. We call this an enharmonic equivalent. Which name we use depends on context and instrument.

Where there are no sharps or flats

There is no tone between E and F, or between B and C - the distance is already just a semitone. This is one of the few 'rules' worth memorising, because it explains the shape of the keyboard and the structure of the major scale.