Sharps, flats and naturals: a simple guide
What sharps, flats and naturals do, how long an accidental lasts, and the easy way to name every black key on the piano.
- A sharp (♯) placed before a note raises it by a semitone.
- A flat (♭) placed before a note lowers it by a semitone.
- A natural (♮) cancels a sharp or flat, bringing the note back to its plain letter.
How long does an accidental last?
A sharp, flat or natural written in the music lasts until the end of the bar. That's why you'll often see a natural sign later in the same bar — it switches the accidental off sooner.
Always Be Careful
A black key to the LEFT of a white key is that note's flat. A black key to the RIGHT of a white key is that note's sharp. So the black key between C and D is both C♯ and D♭ — one key with two names.