Hi All,

I just worked myself through all the chapters of the AB Guide to Music Theory and now have a question about something, which misses a propper explanation.

It states

Both 3/4 and 6/8 have six quavers in a bar, but they are not the same thing. 3/4 means three beats (crotchets) divided into twos; 6/8 means two beats (dotted crotchets) divided into threes.

At an earlier point, we learnt that the upper portion of the time signature represents, HOW MANY BEATS there are in a bar, the bottom figure shows, WHAT KIND OF NOTE represents a beat.

This, however, would mean in my understanding, that 6/8 is 6 beats per bar and the note value is a quaver. Thus, the statement confuses me a bit that it means two beats and dotted crotchets. I mean, its in the end the same, and then again, its not.

Thanks for your enlightening thoughts on the issue.

Hi Lemontree - have you read the chapter which talks about the difference between simple time and compound time? In simple time, the beat can be divided in two (Minims to crotchets, crotchets to quavers, quavers to semi-quavers). Compound time, however, is where the beat divides into threes. Have you seen examples of music which is in 6/8 time? The quavers will generally be beamed in 2 groups of 3, showing that there are 2 beats in the bar. A piece of music in 12/8 time will consist of 4 beats (dotted crotchets) which are divided by 3.

Sorry if this sounds complicated - it's much clearer when you look at music in compound time! How about Handel's Messiah? Check out the start of the Air "O Thou that tellest good tidings to Zion".

yes, @stetenorve, I have. But it doesn't explain, while it suddenly should be crotchets instead of quavers, whereas, the former rule about the meaning of the values/figures in the time signature says otherwise.

Deep breath...

Ok, in compound time (6/8, 9/8, 12/8, but not 3/8) yes, there are 6 or 9 or 12 beats in the bar, but it is often more musical, particularly at a faster speed, to feel the 'beat' as a dotted crotchet.

Therefore, 6/8 has two dotted crotchet beats in the bar, which is equivalent to six quavers. It is similar to 2/4 (simple duple) but with each beat having three subdivisions (which is basically what compound time is) rather than the two you would find in simple time..

So:
6/8 = 2 beats (compound duple)
9/8 = 3 beats (compound triple)
12/8 = 4 beats (compound quadruple)

You can achieve the same effect by using triplets in simple time in order to divide the beat into three.


I wonder how much one can charge for correspondence courses...

Uh oh, maybe that is just another example of me going to deep into that stuff. Maybe you should know about me that I do most of the memorizing by the mathematical rules behind the music. And don't get too much hung up by the fact that I am only preparing for Grade 3. I know what compound time is, I can write it, and I can write it with rests and everything. I even know that Duplets exist and how they are written.

So, the answer to this one would be, it is more convenient to write and count in crotchets, instead of quavers, even though the figure in the time signature speaks of quavers (and, maybe, because there would be no notation equivalent to 2 dotted crotchets in a bar beating two beats)?

It has nothing to do with something like a transposition into simple time would result into triplets of equal beats, but in simple time, the equivalent is two crotchet beats in a bar, thus, the compound time has to relate to that simple time beat, by two beats of said (in compound time dotted) crotchet.

Just as an example of my thinking. Do you understand now, what I am getting at?

Er, yes.

But in your second paragraph, you mean 'it is more convenient to write and count in dotted crotchets instead of quavers', don't you? You've mentioned them elsewhere, so I assume you do.

Also, be careful using words like 'transposition' as that is something else again, nothing to do with rhythm (I think we've been here before!).

Yep. You are right. It should say dotted crotchets there. These are those little things that might cause to ruin my distinction.

Well, I guess, I could say rewriting the piece into simple time instead of transposition.

Yes! Transposition refers specifically to altering the pitch and usually changing key (expect when transposing up or down an octave).

Carl Orff invented a new notation for time signatures, in which the lower number was replaced by a note to represent the time unit, so he could show which of the two versions of 6/8 he meant you to think (or the conductor to beat): either 6 over a quaver or 2 over a dotted crotchet.

I've seen that, but didn't realise it was invented by Orff. What a simple but ingenious idea.

I teach my pupils to relate the bottom note of time signatures to the American note names - this seems to make sense

eg Crotchets = quarter notes 1/4 . Time signature of 3 crotchets in a bar = 3/4
Minims, half notes 1/2, time signatures 2/2, 3/2 etc

When you are counting dotted crotchets, there is no figure to represent a dotted note, so you use the next smallest (quavers) so 2 dotted crotchets becomes 6/8. You have to know that you are counting and feeling/playing 2 beats in the bar.

I don't think convenience is the reason for the note-grouping in compound time.
6/8 not only looks different from 3/4, it sounds totally different too. Just as SueHM explains it to her students.

I think it is better to relate theory to actual music playing, rather than just mathematical derivations. The theory you are learning is after all meant for playing music.

I also have the AB guide and to be honest I was struggling with a few things..I started theory when I started playing which was 6months ago and to behonest I hated theory....I brought the workbooks that go alongside the AB guide and just got really frustrated...Im on grade 3 at the mo...

My teacher is a great help but when I have lessons I would rather use the time to practice and break down my pieces so im trying to mainly self-teach the theory...saying that myy teacher is really good at combining theory into the lesson while playing..

I have just brought - "take 5 and pass first time"and to be honest - its brilliant!!

Its written for people with a bit of knowledge but could be used by beginners too...

I read about normal vs compound time last night and the books explains it so well!!!

The book is in "simple" terms and its very friendly Also gives you stuff to try and breaks it down...plus its only 50 pages.

Honestly - its brill - so much easier to read than AB....Ive resorted to reading that book and have got mock G3, G4 & G5 papers to try out as I wanna take the exam in Nov - this new book has made me feel that I will be able to do it.

Ingenious, maybe, but it doesn't work for me. Orff uses it in Carmina Burana, and I find it unhelpful ... I've tried to analyse why. Perhaps it's because I've learnt (for instance) the code '6/8' and have linked that directly with a feeling (which is two dotted crotchets a bar, I suppose), but I don't consciously think of 6/8 being two dotted crotchets per bar.

Or perhaps having a 2 with a picture of a dotted crotchet underneath involves two different sorts of graphical representations, and a simple trumpet player's brain can't cope. Just give me the numbers, thanks.