Music Theory · 4 min read
Sharps, Flats, and Naturals: Accidentals Explained
The little symbols that nudge a note up or down a semitone — what they mean and how long they last.
A semitone (half step) is the smallest standard distance between two notes. The symbols that move a note by a semitone are called accidentals.
The three symbols
- Sharp (♯) raises the note a semitone. F becomes F♯ — on the violin, your finger slides slightly higher.
- Flat (♭) lowers the note a semitone. B becomes B♭ — your finger sits slightly lower.
- Natural (♮) cancels a previous sharp or flat, returning the note to its plain self.
How long do they last?
An accidental applies to that note for the rest of the bar (measure), and only at that pitch. The next barline cancels it automatically. A natural sign is how you undo a sharp or flat within the same bar.
On the violin, you feel them
Pianists press a different key for a sharp; string players move the same finger a small distance. That's why intonation (playing exactly in tune) is the violinist's lifelong craft — there are no frets to catch you. A tuner is your honest feedback while the ear catches up.
Sharps vs key signatures
When the same sharps or flats appear in every bar, composers move them to the start of the staff as a key signature — it's just a shortcut. Read What is a Key Signature? next.