Accidentals & Enharmonics

The five signs that raise or lower a note, how long an accidental lasts, and why the same pitch can be spelled two different ways.

What's inside

• The five accidental signs — sharp, flat, natural, double sharp, double flat — with what each does
• Rules for how long an accidental lasts: to the end of the bar, one octave only, through a tie, and courtesy accidentals
• All twelve semitones of the octave mapped against the piano's black and white keys
• A table of enharmonic equivalents — one sound, two written names
• Why spelling matters for scales, and how to tell a signature accidental from a bar-only one