I'm quaveringly staring at your crotchet: 3/4 vs. 6/8 time signatures in music

August 6, 2006 8:27 AM

Yeah, but what's the real difference between 3/4 and 6/8 time?

I've sort of developed my own theory, but I still use the terms interchangably in some instances.

I'm wondering whether there is a be-all-end-all way to determine if a piece of music is in 3/4 or 6/8 meter, or whether it's more a matter of personal interpration.

posted by goodnewsfortheinsane to media & arts (23 answers total)

You would want to use 6/8 for faster music, so you wouldn't need to draw (or read) 64th notes all the time.
posted by mzurer at 8:32 AM on August 6, 2006

6/8 feels more "swingy" and fanciful to me. You can conduct it in two.

3/4 always feels more "stable" and proper. There are times when it can be conducted in one, but the music would have to be very fast - and then, as a listener, it is harder to determine which signature it's really using.

I'd say it really can be a matter of personal interpretation. I played saxophone in concert band for over 12 years - there were times where a song we'd played in high school in 3/4 was conducted in 3, then when I got to college and played it again, my new band leader conducted it faster and in one.
posted by ArsncHeart at 8:39 AM on August 6, 2006

3/4 is grouped so that you have 3 sets of 2 quavers, like so: || || ||, where as 6/8 is 2 sets of 3 quavers: ||| |||. If the phrasing/rhythm of a piece naturally falls into the 3 groups, then it is in 3/4, and likewise for 6/8.
posted by Orange Goblin at 8:41 AM on August 6, 2006 [1 favorite]

6/8 has a primary accent and a secondary accent. 3/4 only has a primary accent.
posted by free pie at 8:51 AM on August 6, 2006

Orange Goblin has it. 6/8 vs. 3/4, when used correctly, denote two entirely different styles of music.

A related time signature is 3/8, which can be used for both quick waltzes (|| || ||), and 6/8-style pieces (||| |||). Several Chopin waltzes number among the former, while Beethoven's Fuer Elise (if I'm reading it correctly) numbers among the latter.
posted by The Confessor at 8:52 AM on August 6, 2006

Not really. It really depends on the speed of the piece more than anything else. If the triplets are slow enough that your brain thinks that each triplet is a beat, then the piece will seem like it's in 3/4, while if the piece is sufficiently fast that your brain regards the triplets as "subdivisions" of each beat, then it'll seem like it's 6/8.

There are exceptions to this, of course. For example, Saint-Saëns' Danse Macabre is written in 3/4, despite usually being played fast enough to sound like a 6/8. (This is primarily, I think, because of the "fugue" section in the middle, where the phrases would end up starting in the middles of bars if he didn't write it in 3/4.) From the other direction, the final section of Prokofiev's Scythian Suite is written in 6/4 even though it's taken very, very slowly; this acts as a signal to the artists that the phrase are supposed to be very long, sweeping, and bombastic.
posted by Johnny Assay at 8:55 AM on August 6, 2006

This wiki gives an explanation. I do like the example given in the polymetre section, where "// I-like-to be-in-A // ME RI CA//" shows a 6/8 followed by a 3/4 measure (i.e. two stresses followed by 3 stresses per measure).

See also here, describing the difference between a simple triple(3/4) & compound duple(6/8) meter's beat divisions (former is 1&2&3&, latter is 1&&2&&).
posted by neda at 8:57 AM on August 6, 2006

3/4 is grouped so that you have 3 sets of 2 quavers

And for our chums on the other side of the pond, a quaver == an eighth note.
posted by Handcoding at 8:57 AM on August 6, 2006

Haha, is quaver really just a British term? My ex would use it all the time to sound smart.
posted by dagnyscott at 9:09 AM on August 6, 2006

Yes I think orange goblin is on it. Of course such things are never completely clear cut like Johnny Assay suggests, and of course a really interesting question (which Johnny Assay touches on) is the difference between say 3/4 and 3/8. Some of this gets in to the realm of player-psychology (I mean from a composer's perspective, how to players react when they see a slow 3/8 vs how do they react when they see a fast 3/4) and many composers play with the difference (i.e. Morton Feldman and his relatively fast tempos and 1/8th notes in very slow sounding music) and some composers just seem to deliberately favor 16th or even 32nd notes sometimes just to make things look more complicated than they should be. Of course this is related to how musicians (string players especially) react and play when they see a c-sharp as opposed to a d-flat, but I've probably gone to far away from the original scope of the question.

I guess the point of all this is that sometimes 3/4 or 6/8 can be chosen to create a particular performative effect (imagine watching players have to count in 3/4 when a very strong cross-rhythm is always present, this would create a performative tension that would be impossible to achieve otherwise).
posted by ob at 9:11 AM on August 6, 2006

Another reason specific time signatures are used in ostensibly interchangeable situations is to make the printed notation clearer and easier to read. You certainly could notate a piece in 3/4 as if it was in 6/8, but if the 3/4 quarter notes are subdivided significantly, you might end up with a mish-mash of 32nd and 64th notes in the 6/8 notation.

Same goes for 2/4 vs 4/4!
posted by Aquaman at 9:26 AM on August 6, 2006

Uh, also what mzurer said...

(D'oh!)
posted by Aquaman at 9:27 AM on August 6, 2006

6/8 sounds like triplets in 2/4 time.

For me as a songwriter the two time signatures would affect the phrasing of a piece (a musical phrase corresponds to a sentence in a paragraph so to speak.)

A lot of things in music theory exist simply to make sets of musical rules consistent. A number of things can be notated more than one way, but there is indeed an internal logic to it all.
posted by konolia at 9:32 AM on August 6, 2006

Orange Goblin does have it. 3/4 is grouped || || || (three beats per measure) or occasionally |||||| (one beat per measure), while 6/8, depending on the speed of the piece, is grouped | | | | | | (six beats per measure), ||| ||| (most commonly), or |||||| (one beat per measure).

The relationship between 3/4 and 6/8 is close enough that composers sometimes put 3 beats in a 6/8 measure (possibly against the normal 2 beats) or 2 in a 3/4 measure (possibly against the normal 3 beats). Ob alluded to this. Grouping beats in a way that belies the time signature like this is called hemiola.

Danse Macabre and many waltzes are good examples of pieces in 3/4 that are played with one beat per measure, subdivided in threes.

I like neda's second link.
posted by musicinmybrain at 9:37 AM on August 6, 2006

Ditto Orange Goblin etc.

3/4 = One and two and three and...

6/8 = One two three two two three...
posted by ludwig_van at 10:03 AM on August 6, 2006 [1 favorite]

ludwig van -- that is what I said. A secondary accent. That is what we learned in music school. Of course composers can do anything they want, but technically that is the difference.
posted by free pie at 12:34 PM on August 6, 2006

Sorry, I meant "Ditto Orange Goblin et al."
posted by ludwig_van at 4:47 PM on August 6, 2006

Extra fun fact: writing a bar of 6/8 as three groups of two is called a hemiola.
posted by ludwig_van at 4:50 PM on August 6, 2006

Not mentioned, unless I missed it somehow, is that 3/4 is a simple time-signature while 6/8 is a compound. This is just the theoretical nomenclature getting at what Orange Goblin explains.

A simple time-signature is one in which the measure is divided into the primary beats and then only their typical subdivisions (which include triplets). 3/4 is a simple time signature because the three beats of the measure are the only important and universal (in the work) grouping there is.

A compound time-signature is one in which the measure is divided into the primary beats and another simple division which is at work simultaneously. The 6/8 time-signature is a combination of a stress on a grouping of three beats and a grouping of two beats. The three beats are the quick "one-two-three of eighth notes" and the two beats are the slower "one two" meta-groups of those eighth notes.

While you might think this could have been a 2/2 time-signature using triplets, if you think about why we are calling it a compound signature and how we are counting and thinking about and you'll see why two quarter notes to a measure, each quarter note getting a beat, and using triplets just isn't really a complete combination of those triple and double beats. Quarter notes using triplets puts too much emphasis on those two beats to the measure and reduces the fundamental importance of those groups of three.

The third type of time-signature is the complex time-signature. These are time-signatures with irregular (and I don't mean "irregular" as in "abnormal" but as in "not regular) groupings such as 7/8 which has three groupings of two (unlike 6/8!) with an additional beat tacked on.

It's important to understand that rthymnic notation, much less time-signatures, were a late arrival to the nomenclature of western music. The "beats" themselves in western music preexisted their formalization into the notation we see today and in time-signatures. Practice didn't follow theory, theory followed practice.

So this means that theory, and thus modern notation, is attempting to analytically codify something more intuitive and messier. Even so, this more nuanced version of time-signatures—simple, compound, and complex—is notably more meaningful and helpful than the bare-bones version we're taught when we're first learning an instrument. It's more subtle and interesting than "how many beats per measure and what note gets the beat".
posted by Ethereal Bligh at 7:41 PM on August 6, 2006 [1 favorite]

A nice piece where you can hear 6/8 and 3/4 contrasted back-and-forth in alternating measures is "America" from Leonard Bernstein's musical West Side Story.

"I want to live in A - " is sung as six 8th-note pulses in 6/8 and "me - ri - ca" is sung as 3 quarter notes in 3/4, etc. Not sure if that is how it is written in the score (L.B. might have written the three quarters as a triplet over a 6/8 bar) but the effect is that of switching back and forth from 6/8 to 3/4.
posted by persona non grata at 9:18 AM on August 7, 2006

Incidentally, Wikipedia's main article on time signatures is pretty thorough.

As Ethereal Bligh mentioned, composers may do some whacky things with time signatures. A number of famous orchestral pieces exist in which, for example, some of the instruments are marked in 3/4 and others are marked in 6/8. (Can't think of any examples I'm 100% sure of right now.) Sensemayá, by Silvestre Revueltas, has (if I remember correctly) a bar of 5-and-a-half/8. In this case, that's interpreted as two groups of four sixteenth notes and one group of three.

Irregular compound meters may also have variable grouping even within the same piece. 5/8 may be ||| || or || |||; 8/8 could be || ||| |||, ||| || |||, or ||| ||| ||; and so on. Sometimes composers make this explicit by notating, for example, (2+2+3)/8 instead of 7/8.

Some composers have foregone time signatures altogether when it suited them. Others, such as the late avant-garde composer Iannis Xenakis, have experimented with entirely new forms of musical notation, such as plots of pitch versus time.

All this is way beyond the scope of your question, but I think it's interesting and hope you may too.
posted by musicinmybrain at 5:25 PM on August 9, 2006

"As Ethereal Bligh mentioned, composers may do some whacky things with time signatures."

I don't think I mentioned that, but I'm sure as hell aware of it. Not in the context you mention, but because I'm a percussionist. Composers of solo percussion works sometimes seem to be, well, perverse.
posted by Ethereal Bligh at 7:54 AM on August 10, 2006

I notice that folks that are, as adults, getting into learning music theory are obsessed with time signature. When you first learn what a time signature is, you want to know what time signature everything is in.

But as someone who has been familiar with music theory for a long time, I don't really find myself to be very concerned with what time signature a given piece is in. The fact is you can compose a piece in 4/4 in such a way that it sounds like it's in 7/8 or 9/16 or whatever your heart desires. All you have to do is ignore the barlines.

My point is, worry less about what the time signature is. It's more important to be able to feel the rhythm. Unless you get paid to transcribe music, in which case scratch all that.
posted by Darth Fedor at 5:46 PM on August 26, 2006