Music Theory · Chapter 1, Lesson 4 — Music Theory 101

Sharps, Flats & Naturals

Three tiny symbols that let 7 letters name all 12 notes: ♯ raises, ♭ lowers, ♮ cancels.

Beginner ⏱ 3 min read 🎹 Interactive

Filling in the gaps

The musical alphabet only has 7 letters, but a piano has 12 keys per octave. Sharps and flats are how music names the other 5 — almost always the black keys.

♯ sharp — raise a half step ♭ flat — lower a half step ♮ natural — cancel, back to plain

The same key, two names

Take the black key between C and D. Raise C by a half step and you get C♯. Lower D by a half step and you land on the exact same key — D♭. Same sound, same key, two valid names depending on which direction you approached it from. That's called an enharmonic equivalent, and every black key works this way.

🎹 Sharp / Flat Namer Toggle the naming direction, then click any black key.
Click a black key
Black keys — always sharp or flat White keys — always natural
💡 Rule of thumb: which name you use isn't random — it depends on the key signature of the music. You'll see exactly why once you reach the Circle of Fifths, but for now, either name is correct.

Common questions

What does a sharp (♯) do?

Raises a note by one half step — the next key to the right, black or white.

What does a flat (♭) do?

Lowers a note by one half step — the next key to the left, black or white.

What does a natural (♮) do?

Cancels a sharp or flat, returning a note to its plain, unaltered pitch.

Why does one black key have two names?

Because you can reach it by raising the letter below or lowering the letter above — like C♯ and D♭.

Never guess a note name again

Melody Monkey labels every sharp and flat live as you play, on any instrument.

Open the free app →

Still stuck? Ask Your Personal Music Teacher about Sharps, Flats & Naturals →

Keep learning

Chapter 1, Lesson 5 · NextHalf Steps & Whole Steps Chapter 1, Lesson 6Enharmonic Equivalents Chapter 1, Lesson 3The Piano Keyboard as a Map Chapter 4, Lesson 10The Circle of Fifths