In music, the sharp sign (♯) means “raise the pitch of the note by one semitone.”

Here’s what that means in practice:

• A semitone is the smallest standard step in Western music — the distance from one piano key to the very next one (whether black or white).

• For example:

  • C raised by a sharp becomes C♯ (one half step higher).

  • F raised by a sharp becomes F♯.

A sharp can appear in two main ways:

1. Key signature – tells you that certain notes are always sharp throughout the piece unless otherwise changed.

2. Accidental – placed directly before a note, meaning “play this note one semitone higher than usual” for the rest of that measure.

A little trick to remember it:
If a note is sharp, you give it a “tiny musical boost” upward.