# Time Signature Calculation

How to determine the time signature?

I already got this question wrong from my quiz, and I'm studying for the final for this music theory class. I understand there are

5 quarters notes 1 half note 10 eight notes

I was deciding between 12/8 and 6/8 due to the eight notes and eventually went for 12/8. Could someone help me with how to count this time signature?

• It sounds like 3/4. All of the given options are wrong. ;) And so is the notation. Add two barlines. Commented Mar 11, 2021 at 10:55
• @piiperiReinstateMonica I suppose you mean "add three barlines." Commented Mar 11, 2021 at 14:17
• @phoog Exactly! I was just checking that you're awake. Commented Mar 11, 2021 at 14:30
• Presumably this is the bit of the test where you have to work out what the time signature is, whether it really makes sense to write it that way or not. It's an exercise in deduction. Next will come, 'How could this be better written?', in part b of the test. It's a computer multiple choice, there's no space to put "I wouldn't have done it that way". Commented Mar 11, 2021 at 15:04
• @piiperiReinstateMonica The question clearly states that this is a single measure. Thus, 12/4 Commented Mar 11, 2021 at 15:28

One way to work it out - count the 8ths (quavers).
You get 24 of them, so that's not going to be right for 12/8, nor for 6/8.

So try again, count the quarters - now you get 12 of them.
That means it's certainly not going to be 4/4.

Even by process of elimination, therefore, it must be 12/4
… but you already just confirmed this for yourself - there are twelve crotchets (quarter notes), 12/4.

'scuse the hand-drawn…

• This makes so much sense and thank you for the hand-drawn Commented Mar 11, 2021 at 10:37

Like in maths fractions, number wise, the top number tells 'how many', the bottom number tells 'of what'.

So, counting the whole bar, there are 12 crotchets.That gives you an answer.

And, since 12 should be divisible by 3, and written thus, as in 'lots of 3', that will work.

An explanation rather than a direct answer!

• I kept going with the eighth notes and could not think about counting by quarter notes. This makes so much sense. Thank you very much Commented Mar 11, 2021 at 10:37

One good strategy for multiple-choice questions is process of elimination. To apply that strategy here, look at the beaming of the eighth notes.

12/8 and 6/8 imply groups of three. That is, they are "compound" meters. The beaming does not reflect groups of three. Similarly, the longer note values are not dotted, and there are no instances where a quarter note is grouped with an eighth note. This is clearly not a compound meter, so we can eliminate those choices.

This leaves us with a choice between 4/4 and 12/4. In 4/4, no more than four eighth notes should be beamed together, but here we have a group of six. Without further analysis, we can eliminate 4/4, leaving 12/4 as the only possible answer.

At this point, we might notice that one of the facts given in the question is that the notation is described as one measure. It looks like you're supposed to consider whether bar line have been omitted, but that's not actually what they're asking. They present you with "a given measure," and all you have to do is add up the durations of the notes it contains. This is the equivalent of three whole notes, six half notes, twelve quarter notes, or 24 eighth notes.

Thus, by two independent lines of reasoning, we arrive at the same answer: 12/4.

• I do like a process of illumination - throwing light on the problem...
– Tim
Commented Mar 12, 2021 at 10:31

It's not 12/8 or 6/8 because the bar doesn't add up to either 12 or 6 eighth notes. It's not 4/4 because it doesn't add up to 4 quarter notes. So it must be 12/4.

An unusual question. Partly because it's so simple to answer by simple arithmetic. (@Michael Lee, I'm afraid you badly need to revise your knowledge of basic notation!)

This sort of question is more typically about ADDING barlines, in which case the best answer, based on the note groupings (though the first 4 beamed 8ths are a bit suspect) would have been to make it 4 bars of 3/4.

You don’t have to consider only the rhythm! The melody is also important to define the content and the sense of the phrase.

If we look at the group of the 6 beamed eighth notes you can hear unambiguous a motif of 3/4 which is confirmed by the succeeding half and fourth note.

The beginning of the phrase fits well in a 3/4 time with the underlying harmony, however it isn’t absolutely clear: This could be as well a 6/4 time.

Another appropriate and also possible solution would be to interpret the first half of the phrase by a change of the time signature into 3 bars of 2/4 ... but this would result in a completely different texture.

Edit: If this is a multiple choice, you have to choose 12/4 and surely not 12/8.

12/8 would be 4 x 3/8. There would be only 3 eight notes tied together (like 6/8 and 3/8 rhythms 12/8 is build by dotted quarter and dotted half notes, also a quarter and an eighth note, with other words the subdivision of 3/8 will always be visible!)

• 3/4 is not one of the choices available for the answer. Commented Mar 11, 2021 at 14:36
• I didn’t understand the question as a multiple choice. In this case theres only 12/4 as possible solution. Commented Mar 11, 2021 at 14:43