Skip to main content

Rhythm & Meter

Time Signature

Definition

A time signature is the pair of stacked numbers at the start of the music, such as 3/4 or 6/8. It shows how many of which note value fill each bar, and so how the beats are counted.

A time signature is printed at the start of a piece, just after the clef and the key signature. It looks like a fraction without the line: two numbers stacked on top of each other, such as 4/4, 3/4 or 6/8. It tells you how each bar is measured, and from that you can work out how to count.

Reading the two numbers

So 3/4 means three quarter notes per bar, and 2/2 means two half notes per bar. In simple meters like these, the bottom note is also the beat: you count "1, 2, 3" in 3/4.

Three short treble-clef examples. In 2/4, two quarter notes counted 1 2, then a half note. In 3/4, three quarter notes counted 1 2 3, then a dotted half note. In 4/4, four quarter notes counted 1 2 3 4, then a whole note.
The top number counts the beats in each bar, and the 4 at the bottom makes each beat a quarter note. The second bar of each line holds one long note that fills the whole bar: a half note in 2/4, a dotted half note in 3/4 and a whole note in 4/4.

When the top number is 6, 9 or 12

In compound meters the top number counts the small notes, not the beats. 6/8 holds six eighth notes, but they are grouped in two sets of three, so the music has two beats, each one a dotted quarter. 9/8 has three such beats and 12/8 has four. To find the number of beats in a compound meter, divide the top number by three.

That is why 3/4 and 6/8 feel different even though each bar holds six eighth notes:

Two treble-clef examples. In 3/4, six eighth notes C5 E5 C5 E5 C5 E5 beamed in three pairs and counted 1 & 2 & 3 &, then a dotted half note C5. In 6/8, six eighth notes C5 E5 G5 C5 E5 G5 beamed in two groups of three and counted 1 & a 2 & a, then a dotted half note C5.
Both first bars hold six eighth notes. In 3/4 they are beamed in pairs, making three quarter-note beats: 1 & 2 & 3 &. In 6/8 they are beamed in threes, making two dotted-quarter beats: 1 & a 2 & a. A dotted half note fills the second bar of each.

Symbols instead of numbers

Two time signatures are often written as symbols. A large C stands for 4/4, which is called common time. A C with a vertical line through it stands for 2/2, called cut time or alla breve.

Where it appears

The time signature is printed at the start of the piece, not on every line like the clef and key signature. It appears again only where the meter changes. If the change falls at the start of a new line, the new signature is usually also shown at the end of the line before, as a warning.

Practice reading time signatures with Time Signatures I: Simple Time and Time Signatures II: Compound Time, then try the Meter Detective puzzles.

Common questions

What does 4/4 mean?

Four quarter notes fill each bar, so you count four beats: 1, 2, 3, 4. 4/4 is so widespread that it is also called common time and is often written as a large C.

What is the difference between 3/4 and 6/8?

Both hold six eighth notes per bar. 3/4 groups them in pairs, giving three quarter-note beats (1 & 2 & 3 &). 6/8 groups them in threes, giving two dotted-quarter beats (1 & a 2 & a). 3/4 sways like a waltz; 6/8 rocks in a lilting two.

Is a time signature a fraction?

No, even though it looks like one. 2/4 and 4/8 would be equal fractions, but as time signatures they describe different meters: two quarter-note beats against four eighth-note beats.

Practice it: free worksheets