What is a Time Signature?
A time signature appears at the beginning of a piece of music to show the time or meter of the music. It consists of two numbers on top of each other (a bit like a fraction in math, but without the line). The top number shows the number of beats in every measure (bar). The bottom number shows what type of beats they are. e.g. crotchets (quarter notes), quavers (eighth notes), semiquavers (sixteenth notes), etc..
Why do we need a Time Signature?
Theoretically, music does not need a time signature. When counting the beat of a piece of music we could start at the number “1” and keep going to whatever number we got to by the end of the piece. However, there would be 2 main problems with this approach….
- We would soon lose count! Similar to the way we don’t like to go beyond “G” in the alphabet, we musicians don’t really like to count beyond “4”. Sometimes we’ll go to 6 and, if we’re really pushed, we may even count as high as 12!! But, we tend to like 3 or 4!!
- We would not establish a “groove”. The groove (or the “feel”) of a piece of music stems largely from how the beats are grouped together. The feel of a Viennese Waltz and a march differ for a wide variety of reasons, but a key foundation is the different groupings of the pulse.
Let me explain…
If I was teaching you how to march then I would probably stand in front of you and shout “1-2-3-4” at a suitable speed for you to walk in time to.
My natural instinct would be to then start at “1” again rather than going on to “5-6-7-8…”.
This is because it “feels” like the right and natural thing to do. Something in me makes me want to arrange my counting into groups of 4.
In music, these “groupings” are called measures or bars. As a result, a march-like piece will have 4 beats in every measure and these beats will most likely be quarter notes (crotchets).
So, the time signature would have a number “4” at the top (4 beats in every measure) and a number “4” at the bottom (these beats would be quarter notes (crotchets)).
However, if I was teaching you how to waltz (an unlikely scenario given my lack of ability on the dance floor(!!)) then I would want to count “1-2-3” and then return to “1” because this is the grouping that fits with the dance steps:
As a result, the top number of the time signature for a waltz would be a “3” (3 beats in every measure) and the bottom number would probably be a 4 again (quarter notes).
The first beat of every measure/bar is accented (played slightly louder) and this helps to give the characteristic feel of a particular grouping.
What do Time Signatures show?
As we have discussed, a time signature is made up of 2 numbers (one on top of the other) found at the beginning of the stave.
It shows 2 things:
- How many beats are in a bar (top number)
- What type of beats they are (bottom number)
Top Number
The top number is easy to understand.
If it is a “2” then you should count the pulse in groups of 2 and each bar should add up to 2.
If it is a “3” then the pulse will be counted in groups of 3 and each bar will add up to 3.
If it is a “4”, etc…… You get the idea.
Bottom Number
The bottom number is slightly more tricky to understand.
It tells you what type of beats you are counting.
If the bottom number is a “2” then it is a half note beat;
if it is a “4” then the beat is a quarter-note beat;
if it is an “8” then the beat is eighth notes, etc..
It’s really important to keep this in mind when you’re looking at a piece of music.
Here is an summary of what the bottom numbers mean:
Common Time and alla breve
Quite often you will see what looks like a large “C” at the start of a piece of music instead of the usual time signature numbers. This is either common time or alla breve depending on whether the C has a line through it or not.
A “C” without a line through it is called Common Time and is exactly the same as a 4/4 time signature:
A “C” with a vertical line through it is called alla breve and is the same as a 2/2 time signature:
Time Signature Examples
Here are some other common time signatures that you will come across in music:
Beware the changing Time Signature
The thing you must do when looking at a piece of music for the first time is check to see whether the time signature changes at all.
Sometimes a composer will put a new time signature in during a piece of music.
It’s really important that you have a look through before playing a piece because a change of time signature which catches you unaware can totally wreck your performance.
If you’re playing as part of a group or a band then it can spell real trouble!!
