Sharps, Flats and Naturals: Reading Accidentals on the Staff

Sooner or later a small symbol appears in front of a note: a sharp, a flat or a natural. Together these are called accidentals. They tell you to play a key other than the plain white key you would normally play. There are only three common symbols and a few rules about how long they last, so they are quick to learn once you have the plain note names down.

This guide assumes you can already name notes on the staff. If not, start with the beginner's guide to reading piano notes.

What sharps, flats and naturals do

A sharp (♯) raises a note to the very next key up. A flat (♭) lowers it to the very next key down. A natural (♮) cancels a sharp or flat. "The very next key" means the nearest key of any colour, which is one semitone (half step) away.

On the keyboard, the very next key is usually a black key:

• F♯ is the black key just right of F.
• C♯ is the black key just right of C.
• B♭ is the black key just left of B.
• E♭ is the black key just left of E.

The note keeps its letter name and its place on the staff. F♯ is still written on the F line or space. The symbol only changes which key you play.

When a sharp or flat is a white key

There is no black key between E and F, or between B and C, so a few sharps and flats land on white keys.

You will not see these often in beginner music. They appear in keys with many sharps or flats, where the music theory calls for that letter name. When you do meet one, just go to the next key up or down, whatever its colour.

How accidentals are written on the staff

The accidental goes immediately before the note, on exactly the same line or space as the note. The middle of the sharp or flat sign sits on that line or space.

In note names the accidental comes after the letter (F♯, B♭), but on the staff it is written before the note. That way you see it before you play.

How long an accidental lasts

An accidental lasts until the end of the bar. Every later note on the same line or space in that bar is also sharp or flat, even without its own sign.

The rules in full:

• The accidental applies to the same line or space for the rest of the bar.
• A bar line cancels it. The next bar goes back to normal, or to the key signature.
• A natural sign cancels it straight away within the bar.
• If the note is tied across a bar line, the tied note stays sharp or flat.

Some music adds courtesy accidentals (sometimes in brackets) in the next bar as a reminder. They do not change anything. They just save you from wondering.

Key signatures

A key signature is a group of sharps or flats written at the start of every line, just after the clef. Those notes are sharp or flat throughout the piece, in every octave, unless an accidental changes them.

For example, G major has one sharp, F♯. With that key signature, every F you see is played as F♯, whether it is on the top line of the treble staff or anywhere else. F major has one flat, B♭, so every B is played as B♭.

Key signatures always follow a fixed order.

Order of sharps: F C G D A E B. A common phrase is Father Charles Goes Down And Ends Battle.

Order of flats: B E A D G C F, the same list backwards. Try Battle Ends And Down Goes Charles' Father.

A key with two sharps always has F♯ and C♯. A key with three flats always has B♭, E♭ and A♭. You never get a key signature with only C♯, for example.

Each key signature is also shared by one minor key. G major and E minor both have one sharp, for example. Two quick tricks for working out a major key from its signature:

• Sharps: the key is one semitone above the last sharp. The last sharp in D major's signature is C♯, and one semitone up is D.
• Flats: the key is the second-to-last flat. In B♭, E♭, A♭ the second-to-last is E♭, so the key is E♭ major. (F major, with only one flat, is the one to memorise.)

Enharmonic notes: one key, two names

Every black key has two names: a sharp name and a flat name. Notes that sound the same but are written differently are called enharmonic equivalents.

Which name you see depends on the key of the piece. In D major the black key between F and G is written F♯. In D♭ major the same key is written G♭. On the staff they look different, because C♯ sits on the C position and D♭ on the D position. Your fingers play the same key.

Double sharps and double flats

You will rarely need these as a beginner, but it helps to recognise them.

• A double sharp looks like a small bold x. It raises the note by two semitones. F double sharp is played as G.
• A double flat looks like two flat signs, ♭♭. It lowers the note by two semitones. B double flat is played as A.

They appear in keys that already have lots of sharps or flats, where a note needs to go one step further.

Reading accidentals while you play

Accidentals add one more thing to notice, so build the habit in steps. Before you play a piece, look at the key signature and name its sharps or flats out loud. Then scan the music for accidentals and say which key each one means. As you play, keep the current bar in mind: once a sharp or flat appears, it stays in force until the bar line.

If you practise with a digital piano, you can connect it to a note-reading app so your answers come from the keys you play. See how to connect a digital piano by Bluetooth or MIDI for the steps.

Common mistakes with accidentals

• Forgetting the key signature. Glance at it before you start, and say the sharps or flats out loud.
• Forgetting that an accidental lasts the whole bar. If the first F in a bar is sharp, the later Fs on that line or space are sharp too.
• Carrying an accidental into the next bar. The bar line cancels it, unless there is a tie.
• Assuming every sharp is a black key. E♯ and B♯ are white keys.
• Reading the accidental with the wrong note. The sign belongs to the note just to its right, on the same line or space.

Once the plain note names are secure, accidentals become a small extra step. The quickest way to get comfortable is to read real music in a few easy keys. A tune like Twinkle Twinkle Little Star is a good place to try a new key once you know it in C.