Time Signatures

A time signature is a symbol which we write at the beginning of a piece of music to show how many beats there are in one bar.

Time signatures are made of two numbers, one on top of the other.

Here’s a time signature:

3/4 time signature

Time signatures are written after the clef and key signature, and only appear at the beginning of a piece of music, not on every stave.

Grade One Music Theory Exam Requirements

In Grade 1 music theory (ABRSM and Trinity boards) you need to know three time signatures: 2/4, 3/4 and 4/4.

The Lower Number

The lower number in a time signature tells you the type of beat we need to count in each bar.

The number 4 represents a crotchet (quarter note) beat. So, in Grade One music theory we only need to think about counting crotchets, because the lower number is “4” in all three time signatures you need to know at this grade.

The Top Number

The top number tells us how many beats we need to count in each complete bar.


2/4 time signature

means we should count two crotchet (quarter note) beats in each complete bar.

3/4 time signature

means we should count three crotchet beats per bar and

4/4 time signature

means we should count four crotchet beats per bar. This time signature is sometimes shown with the  letter “C” instead of 4/4. It’s often called “common” time, but actually the “C” doesn’t stand for “common” – its history dates back hundreds of years, to before modern time signatures were invented.

C common time

Bar lines

We draw vertical bar lines through the stave to divide the music up into complete bars.

(Sometimes the first and last bars of a piece can be incomplete, but all the bars in between must be complete ones).

Here’s an example in 2/4:

2/4 melody

The values of the notes in each bar always add up to two crotchet (quarter note) beats.

Here’s an example in 3/4. This time the first bar is incomplete:

3/4 melody

The values of the notes in each bar add up to three crotchets, except in the first and last bars which are incomplete.

Working out the Time Signature

In the Grade 1 music theory exam, you might have to work out the time signature of a short piece or some bars. 

Don’t forget that in the exam, you only need to know 2/4, 3/4 and 4/4, so the right answer must be one of these three. 

To work out the time signature, add up the note values in one bar, counting a crotchet as 1.

Remember that a quaver = ½ a crotchet, a semiquaver = ¼, a minim=2 crotchets and a semibreve = 4. Also, don’t forget that a dot increases the length of a note by half of its value.

When you are practising, write them out, like this:

note values

Count up the notes in each bar, and work out how many crotchets (quarter notes) each bar is worth. 

counting notes

Bar 1 is worth four crotchets (and so are all the others). Four crotchets per bar means the time signature is 4/4.

Here’s another example:

working out the time signature

There are 2 crotchet beats per bar, so this is 2/4 time.

Adding Missing Bar Lines

In your music theory exam, you might have to add the missing bar lines to a short tune with a given time signature.

Let’s work out where to put the bar lines in the following melody. Use the same method: count the crotchet (quarter note) beats. The first bar line has been given.

adding bar lines

First, look at the time signature. How many beats do you need to count? (Don’t forget, the top number on the time signature tells us how many to count.)

In this melody, the time signature is 3/4, so we need to count three crotchets in every bar.

Start by grouping together fractions to make up complete beats.

add the notes

Then add the beats together, until you reach the number you need – remember it will always be 2, 3 or 4 crotchets in the Grade One music theory exam, and add a bar line.

add fractions

If you are doing a written exam, make sure that your bar lines are properly vertical (not leaning to one side or the other), that they don’t poke up higher or lower than the staff, and that they are placed about one note-head’s width away from the note on the right. Look at the first bar line that you were given as an example, and use it as a guideline. 

Click here for a complete time signature chart (includes all time signatures – not just those on the grade 1 syllabus!)

Time Signatures Exercises

Hover your mouse over the questions to reveal the answers. (Tap on mobile devices).

a. Give the meaning of the “3” in the time signature 3/4.

b. True or False? The time signature 4/4 means there are four crotchet (quarter note) beats per bar.

c. Add the time signature to each of these melodies.













d. Add the missing bar lines to these melodies. Each one starts on the first beat of the bar.