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

First of all, when it comes to distinguishing 3/4 from 3/8, it is important to know that there are no sound differences between the two. Also, 3/8 is almost never used because there is 3/4. The only time you would see 3/8 is maybe in a 6/8 song, where they throw in a 3/8 measure.

Now, when it comes to distinguishing the time signature, it is important to understand the strong/weak beat patterns:

2/2 or 2/4: For each measure, the first beat is strong, and the second beat is weak. So it follows this pattern: S W.

3/4: S W W

4/4: S W M W (the M is a medium-strong beat, meaning stronger than the weak beats, but weaker than the strong beats).

5/4: Either S W W M W (most likely scenario) or S W M W W

6/8: S W W M W W

7/4: Either S W M W S W W (most likely scenario) or S W W S W M W (basically it either sounds like 4/4 with a 3/4 measure following each measure, or 3/4 with a 4/4 measure following each measure)

8/4 does not exist.

9/8: S W W M W W M W W (it may sound like 3/4 where each beat has a triplet)

10/4: S W W M W W S W M W or S W M W S W W S W W (basically a combination of two 3/4 measures and one 4/4 measure, because 3 + 3 + 4 = 10)

I have never seen a song in 11/4, nor have I even seen it written in advanced music theory. If a song is ever in 11/4, you would just be able to tell because of how weird and messed up the song sounds.

12/8: S W W M W W MS W W S W W (MS is stronger than the medium beat, and weaker than the strong beat; also, 12/8 is rarely used; composers normally use 6/8 with the exception of Chopin in his Nocturne in Eb Major, Op. 9 No. 2)

When it comes to distinguishing between 2/4 and 4/4, I look at it like this: If the song has a drum set, it makes it more obvious. If it follows the pattern of kick-snare-kick-snare-kick-snare..., it's in 2/4 (or 2/2). If it adds some sort of articulation to the second kick (like if it counts like: 1 2 3 + 4), it's in 4/4. Usually, the kick would be on the upbeat of 3, or the high-hats may have some sort of articulation.

If it has no drum set, then you try and feel out the groove of the song. Usually, the third beat of 4/4 isn't much stronger than the weak beats. So, it would feel like this: One Two Three Four One Two Three Four.... However, 2/4 feels like this: One Two One Two One Two....

The difference between 3/4 and 6/8 are very similar to the difference between 2/4 and 4/4. A drumbeat would go One Two Three One Two three in 3/4, and in 6/8 it would go One Two Three Four Five Six One Two Three Four Five Six..., usually adding a snare on beat four. If there's no drum set, then you would still feel the groove of the beat (or the swing of the beat).

6/8 and 12/8 have very slight differences. In 12/8, the seventh beat is only slightly stronger than the rest of the beats, but it's not as strong as a strong beat. Usually, a melody will match up to either six or twelve beats. If the melody repeats or can repeat below twelve beats (so basically six beats), it's 6/8. If the melody repeats or can repeat only on multiples of twelve (mostly just 12 beats), than it's 12/8. Keep in mind that 12/8 is far less common than 6/8.

The difference between 3/4 and 9/8 is simple: if each beat in 3/4 is straight (so it uses quarter notes, eighth notes, sixteenth notes, or the like), then it is simply 3/4. If each beat is a triplet (or has a triplet sound, meaning it sounds like there is a triplet on each of the three beats), then it's 9/8.

There is no sound difference between 6/4, 6/8, and 6/16. However, 6/8 is used far more commonly than 6/4 or 6/16. I highlighted it below:

2/2 2/4 2/8 2/16

3/2 3/4 3/8 3/16

4/2 4/4 4/8 4/16

5/4 5/8 5/16

6/4 6/8 6/16

7/4 7/8 7/16

There is no such thing as 8/4, 8/8, or any measure with eight beats.

9/4 9/8 9/16

10/4 10/8 10/16

Like I said before, I don't know if 11/4 exists as a standalone song. If anything, an 11/4 or 11/8 or 11/16 measure is added in the middle of a song for an articulation effect. If anyone knows of this definitely, then please tell me because it's very interesting!

12/4 12/8 12/16

There are never any occurrences of 13/4, 14/4, 15/4... that make it common enough to take note on, besides the couple of songs out of the millions and billions of songs in the world. Basically, never ever worry about these time signatures.

I hope this helped, James KI, and all other people who struggle with this issue!

Edit: The Mario Kart 64 Result 1 song (the song when you win) is in 11/8 time. So, I guess they do use it.

Answer 2

I'll try to give a somewhat simpler answer than the others posted so far.

The top number in the time signature tells you the feel of the musical beat:

• 2 is a marching feel: one-two, one-two, one-two.
• 3 is a waltz: one-two-three, one-two-three.
• 4 is often called 'common time': one-two-three-four, one-two-three-four.

The 'one' beat is (almost) always slightly stronger than the others. That's how you identify the feel - listen for where the repeating emphasis lies and count along. Sometimes it can be difficult to decide if a piece is in two-time or four-time. If in doubt, remember that four-time is much more common.

The bottom number in the time signature is purely notation, and tells you how each beat would be written down. 4 indicates a quarter-note (crotchet), 2 indicates a half-note (minim), etc. You can change this bottom number and re-notate the music using the new beat value throughout and it will sound exactly the same. The best bottom number to use is whichever makes the music easiest to read. It's almost always 4.

Putting that together, as an example, 3/4 tells you that you count in three (waltz) and that you are counting quarter notes (crotchets). So there are three quarter note beats to each measure (bar).

I need to mention here that each beat can be subdivided, and our notational system subdivides beats into two, four, eight, and so on - halving each time. For example, although the feel of a march is one-two, one-two, that can be subdivided into one-(and)-two-(and), one-(and)-two-(and). That's how we can have notes that are faster than the main beat.

But sometimes you want to subdivide into three instead of two - imagine 'Humpty Dumpty sat on a wall' - one-(and-a)-two-(and-a), one-(and-a)-two-(and-a). In notation, these are called triplets.

To make subdivisions other than two more convenient to notate, we have 'compound time signatures' that follow slightly different rules. The top number is no longer the number of beats and the bottom number is no longer the notational value of each beat. It's easiest to explain with examples:

6/8 is the most common compound time signature. It is counted in two, just the same as 2/4, but each beat subdivided into three instead of two. So the time signature tells you literally there are six eighth notes to a measure (bar), but you have to use your knowledge of compound time signatures to know that you should count it in two, not in six.

Likewise, 9/8 is counted in three (like 3/4) and 12/8 is counted in four.

That covers most music you will encounter. There are more exotic compound time signatures where not all of the beats are the same length. For example 7/8 could be counted as one-(and)-two-(and)-three(-and-a), one-(and)-two-(and)-three(-and-a) - that is with the third beat longer than each of the other two. Don't worry about these until you are comfortable with 'normal' time signatures.

Answer 3

Every piece of music (almost...) has a 'feel' to it. A pulse. That is intrinsic with the piece. Often, it's only after a piece has been made up that a time signature becomes apparent. It's needed mainly so that the piece can be written in order that others may read and thus play it.

Mainly in music, we count in twos and threes. With bigger numbers in time signatures, there is the tendency to split them into twos and threes again.

The majority of music has a rhythm running through it. One taps ones foot, nods ones head in time to that rhythm. There will be a recurring point which feels like a pulse. For convenience's sake, music says that heavier moment is the downbeat - the first beat of a bar. With music that keeps a pattern going, that will repeat, as patterns do. When the next emphasised point arrives, that's the beginning of the next bar. It's simple to divide music up in this way, both for writing and reading.

By counting the sub-divisions between main emphases, we can count a number. Sometimes it's two, sometimes three or four. That tells us what the top number could be in the time sig. The bottom number is a little arbitrary. It's often 4, which signifies crotchets, or one beat notes, sometimes called 'quarter notes', as the most common time sig. is 4/4, those 4 notes filling one whole bar.

Sometimes, the pattern is 1-2-3, 1-2-3, 1-2-3 etc. So here, it'll be what those in US call three-quarter time, written 3/4.

Odd time sigs are more easily countable in, as previously stated, 2s and 3s. So 5/4 could be 1-2-3, 1-2. 1-2-3, 1-2. 7/4 may be 1-2, 1-2, 1-2-3. Greek music may be 13/4, which can be counted as 1-2-3, 1-2-3, 1-2-3, 1-2-3-4. All numbers counted in equal time, of course!

If a piece is a faster one, it's more convenient to write shorter notes, thus quavers (one eighth notes), although they're not necessarily half as long as the crotchets in another piece! It depends on the b.p.m.

There have been several similar questions over time here, please read them and their answers, too.