3. Time Signatures
- Category: Grade 5 Online Course
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Grade Five Music Theory - Lesson 3: Time Signatures
To read this page with US terminology (e.g. "quarter note" instead of "crotchet") hold your mouse over any underlined word.
The time signature tells you how many beats there are in each bar, and how long each beat is.
A time signature is made up of 2 numbers, one written above the other.
For example, like this:
The lower number tells you what value of note to count:
The lower number 4 tells you that the kind of note we must count is a crotchet because the number 4 (in the lower position) stands for crotchet.
The numbers you can find in the lower position are:
The upper number tells you how many of these beats you need. So,
means we have 2crotchets per bar
means we have 6quavers per bar, and
means we have 4minims per bar.
The time signature must appear at the beginning of a piece of music, after the clef and the key signature. The order that these 3 symbols must be written is always Clef-Key-Time. This is easy to remember, as the letters CKT must be in alphabetical order!
clef - key - time
Although the clef and key signatures must be repeated on every new line of music, the time signature is not repeated:
We can describe every time signature in a technical way, and there are two parts to the description.
Every time signature is:
Simple or compound
AND if it's simple or compound, it will also be
Duple, triple or quadruple.
For example, 4/4 is a “simple quadruple” time signature. 6/8 and 6/4 are both “compound duple” time signatures.
You might get a question in Grade Five Theory asking you for the technical name of a time signature.
Describe the time signature as
: simple or compound _______________
: duple, triple or quadruple _________________
How do I work out the technical name?
You work out the technical name by looking at the upper number of the time signature. You will need to learn this table:
So, 4/4 is “simple quadruple”, and so are 4/2 and 4/8 (rare), because the upper number is 4.
3/2, 3/8 and 3/4 are all “simple triple” time signatures.
If the upper number of the time signature isn’t in this table, then the time signature is called irregular. “Irregular” time signatures are not qualified with “duple”, "triple” or “quadruple”, they are just called “irregular”.
For example, 7/8 and 5/4 are “irregular” time signatures.
A whole bar is always divided into beats. There can be 2, 3 or 4 main beats in a bar, (except in irregular time- see below).
- Duple=2 beats per bar
- Triple=3 beats per bar
- Quadruple=4 beats per bar
We never usually have more than 4 main beats in a bar. If the upper number in a time signature is higher than 4, you can divide it by 3 to find out how many beats there are:
|Upper number||/3||=beats per bar|
Irregular time signatures are a combination of duple, triple and/or quadruple times.
For example, 5/4 has five crotchets per bar. These crotchets can be grouped as 2+3, or 3+2. 7/8 has seven quavers per bar. These can be grouped as 3+4, 4+3 or even 2+3+2. The composer will use phrasing marks, (and beams on quavers or smaller notes), to indicate the groupings he/she wants.
This composer wants a 3+4 grouping.
As we have just learnt, there must be 2, 3 or 4 beats in a bar (except in irregular time).
In simple time, the beat is always undotted, and it is divided into 2 sub-beats:
In compound time, the beat is always dotted, and it is divided into 3 sub-beats:
There are 4 types of question:
- Putting barlines in an extract with a given time signature.
- Putting a time signature in an extract with given barlines.
- Rewriting music in a new time signature without changing the rhythmic effect.
- General knowledge questions about the technical names of time signatures.
You won’t get every type of question in your exam, but any of them can come up, so be prepared for all of them!
Look at the lower number in the time signature. This tells you the kind of note to count:
= count minims
= count crotchets
= count quavers
= count semiquavers
Next look at the upper number. This tells you how many of these notes there need to be in each bar. (Don’t forget to check whether the piece starts on the first beat of the bar or not- the instructions will tell you this.)
Draw a barline after each complete bar.
Here’s an example.
Add the missing bar-lines to the following, which starts on the first beat of the bar:
The time signature tells us to count four crotchets per bar, and the instructions tell us to start counting on the first beat of the bar. So, let’s draw the first barline after the first four crotchet beats, which I’ve marked above the stave:
Notice that the notes don’t have to actually becrotchets. In the first bar, there is a dotted crotchet worth 1? crotchet beats, and a quaver which is ?, plus two crotchets = 4 crotchet beats. In the next bar we first have a minim (=2 crotchet beats) and two crotchets, making four crotchet beats in total:
Continue in the same way until you get to the end of the piece:
In this case, the last bar doesn’t get a barline because there are only three beats in it, and we can see that the piece isn’t finished because of the “etc” marking at the end.
First you need to decide whether the time is simple/compound or irregular.
Here are some useful things to look for when deciding if the music is compound or simple time:
|Simple Time||Compound Time|
|Dotted notes are rarely followed by dotted notes of the same value.||Dotted notes are often followed by dotted notes of the same value.|
|Quavers are grouped into 2 or 4.||Quavers are grouped into 3.|
|Triplets can occur.||Duplets can occur.|
|Semibreves can occur.||Semibreves rarely occur.|
Second, work out the type of beats to count in a bar.
Third, count them!
If the music is in simple or irregular time:
- the main beat will be undotted, and notes will be grouped in twos.
- Always start by trying to count crotchet beats (lower number will be 4), as these are the most common. Here are some examples:
- If crotchets work, stick with crotchets!
- If there are no quavers (or smaller notes), you could count minim beats instead (lower number will be 2):
- (There isn’t a big difference between 2/2 and 4/4. There is a difference between 3/2 and 6/4 though - 3/2 is simple time and 6/4 is compound).
- If the total number of crotchet beats in the bar isn’t a whole number, try counting the quavers (lower number will be 8) instead:
- If the total number of quaver beats in the bar isn’t a whole number, try counting the semiquavers (lower number will be 16) instead. These time signatures are very rare though!
If the music is in compound time:
- the main beat will be dotted, and notes will be grouped in threes.
- If the main beat is a dotted minim, and crotchets are grouped in threes, count the crotchets (lower number will be 4):
- If the main beat is a dotted crotchet, and quavers are grouped in threes, count the quavers (lower number will be 8):
- Compound time signatures with an 8 are the most common type.
- If the main beat is a dotted quaver, and semiquavers are grouped in threes, count the semiquavers (lower number will be 16):
In Grade 5 Theory you might be asked to rewrite a short excerpt using a different time signature without changing the rhythmic effect.
This is easy if both the old and new time signatures are simple time.
Notice how the note values change when 3/4 becomes 3/8:
Each note value is halved; for example, a minim becomes a crotchet and a dotted minim becomes a dotted crotchet.
The task is more complicated when you are moving from simple time to compound time or vice versa.
The first step is to look at the two time signatures and remind yourself what kind of beat and how many beats each signature represents.
You might have an extract in 12/8 to rewrite in 4/4:
12/8= 4 dotted crotchet beats per bar
4/4= 4 crotchet beats per bar
so, each dotted crotchet in 12/8 should be written as a plain crotchet in 4/4:
Now think about how the beats are divided into sub-beats:
|12/8: 1 dotted crotchet=3 quavers (1 quaver= a third of a crotchet)|
|4/4: 1 crotchet=2 quavers (1 quaver= half of a crotchet)|
In order to keep the rhythmic effect when re-writing the rhythm, you will need to use duplets or triplets.
- Duplets are used in compound times (3 becomes 2)
- Triplets are used in simple times (2 becomes 3)
Let’s look at an example:
Duplets are used in compound time, when you need 2 notes instead of 3.
Triplets are used in simple time, when you need 3 notes instead of 2.
Rests sometimes make the exercise look more difficult, but you should think about them in exactly the same way as you think about notes.
A common mistake, (especially with compound times), is to forget that a rest sometimes makes up a whole beat with the note before it.
In this bar, the 9/8 time signature might make you think that you should group quavers into threes, so you might think the second beat of the bar starts with the quaver rest.
Look more closely, and you’ll see that the first complete beat, (which must be a dotted crotchet beat), is the G plus the quaver rest. The second beat is the duplet B - D, and the third beat is C sharp - A. Rests can be included in duplets and triplets in the same way that notes can. Here’s an example:
Make sure you don’t forget to add a phrase mark to indicate where your duplet or triplet starts and ends, and write the 2 or 3 symbol on the same side of the note.