Time signatures

A time signature is two numbers at the start of a piece, stacked like a fraction but not one.

• Top number — how many beats in a bar. (In compound time, such as 6/8, it counts the smaller notes instead — see below.)
• Bottom number — which note value counts as one beat.

The bottom number is written as a denominator: 4 means quarter note, 8 means eighth note, 2 means half note.

So 4/4 is four quarter notes per bar. 3/4 is three. 6/8 is six eighth notes.

The common ones

The C and ¢ symbols, and each of these signatures in real notation, are in the time signature symbols section of the music symbols dictionary.

Simple vs compound time

This is the distinction that matters and the one most explanations skip.

In simple time, each beat divides into two. 4/4, 3/4 and 2/4 are all simple.

In compound time, each beat divides into three. 6/8, 9/8 and 12/8 are compound.

Which is why 6/8 is not "3/4 played faster". In 6/8 you feel two beats per bar, each a dotted quarter, each split into three eighths. In 3/4 you feel three beats, each a quarter, each split into two. The bar contains six eighth notes either way — the grouping is completely different, and so is the music.

Count them out loud and you can hear it immediately:

• 3/4 — ONE two three, ONE two three
• 6/8 — ONE two three FOUR five six

Quick check

A bar of 6/8 has how many beats you would actually feel?

TwoThreeSix

Where the accent falls

Every meter has a natural stress pattern, and this is most of what a time signature actually communicates:

• 4/4 — strong, weak, medium, weak
• 3/4 — strong, weak, weak
• 6/8 — strong, weak, weak, medium, weak, weak

Composers play against these constantly. Syncopation is only interesting because there is an expected accent to contradict.

Odd and changing meters

5/4, 7/8 and similar are usually felt as uneven groupings — 7/8 as 3+2+2 or 2+2+3, for instance. Some pieces change signature bar to bar. Neither is exotic; both follow the same two rules from the top of this page.