Understanding Time Signature: How do I identify the time signature of a song?

Question

I have played music for years and I still don't understand what a time signature actually signifies. I understand it from a superficial sense. If given sheet music I could tell you what time signature it is written in. But why is written in that time signature and what impact does it have on the music? Why would something be written in 3/4 and not 3/8? Or for that matter, why not something completely different like 7/8 and add rests to the end. Nor can I figure out how any of this impacts how the music sounds. I feel it is purely notation, yet, some time signatures are common in some genres of music. Furthermore, I have heard multiple people use the phrase that a piece is "played in so or so time signature". How do they know that from just listening to the piece? I am interested in composition and am revisiting the fundamentals. This is something that I have been stuck on and unable to find online.

Answer 1

The answer is probably much easier than you think. The easiest way to identify it is to listen for the accent or the beat that is loudest and follow the change in chord progressions. In the lines below, say the capitalized words louder than the lowercase words, in a rhythmic beat

Here's 3/4

3: ONE two three ONE two three ONE two three ONE two three

4: ONE TWO THREE FOUR

Here's 6/8

6: ONE two three four five six ONE two three four five six

8: ONE TWO

And on up to 8

Here's 4/4

4: ONE two three four ONE two three four ONE two three four ONE two three four

4: ONE TWO THREE FOUR

Answer 2

Answer 3

In some cases music can be notated in different ways. So you can write in either 3/4 or 3/8 and not technically be wrong either way. But then you have to factor in the nuances like beats per minute.

For this I'd encourage you to use your ear. Pull up musescore or some other free notation editor. Write the same thing in several ways with the same tempo. Find the accented down beats. Listen to how the tempo affects the interpretation of the rhythm value.

You might find nothing changes, or you might find that one is 2x speed as the other. And one may have a weird delay at the end of a measure.

You'll find 3/4 and 3/8 are more closely related than 3/4 and 6/8 in terms of downbeat accent. 3/8 runs faster. etc.

Just keep in mind the notation isn't the music, It's a record of how to play the music. I don't feel like how you get there is all that important.

Answer 4

A time signature is a figure that describes the meter (it's sometimes called a meter signature). The meter of a piece of music is a pattern of accented (stressed) and unaccented (unstressed) beats.

Take a waltz—it's pretty easy to hear ONE, two, three, ONE, two three as the pattern of accented and unaccented beats—the first beat of every three is stronger (louder, usually) than the other two. In a march or polka, it's ONE, two, ONE, two. In most pop music, it's ONE two THREE four, ONE two THREE four, where three is a little stronger than two or four but not as strong as one.

When writing a time signature for a piece of music, you pick one that matches the meter, the pattern of stresses in the music. Here's the thing: by ear, you cannot tell the difference between 3/4 and 3/8, which have the same pattern, or between 2/4 and 2/2. Different genres of music with the same type of meter are written in certain time signatures by tradition, mostly—polkas are usually in 2/4, marches are usually in 2/2.

...if you added rests to the music and wrote it in 7/8 (assuming it wasn't really in 7/8), then whenever someone tried to perform it, they'd perform the rests, interrupting the music frequently.

Does that help? Feel free to ask a followup.