8-Part Harmony

I've become a bit confused about this topic.

I've read that harmony in more than four parts is unsually just four-part harmony with some of the voices doubled in another octave, but I've also read that, even in 6, 7, or 8 part harmony you should avoid having parallel octaves with the uppermost voice. It seems as if doubling any part in a higher octave results in parallel octaves in the uppermost voice.

Can anyone shed some light on this matter?

Thanks

Don't confuse the fact that any note can be doubled at the octave, with parallel octaves.

parallel octaves require horizontal movement.

Any triad has only 3 notes, so even in 4-part harmony, at any single time, at least one note WILL be doubled in another octave or at the unison.

7th chords give you a tiny bit of leeway, since they are in effect 4-note chords, but you can't write an entire piece in 7th chords (well, yes, you could, but it wouldn't be common-practice harmony, which is, I presume, the topic you are interested in by asking this question).

In orchestral writing, what can appear to be 8-part writing (for example a full string section of 1st and 2nd violins, violas, cellos - contrabass often doubled at the octave the cello part, with let's say 4 horn parts) is often simply 3 and 4-part harmony, with various doublings at the octave.

A line that regularly doubles at the unison or octave is, in effect, not "a part". We would not consider that 5th string part (the contrabass) as an independant voice if it were always doubling the cello part.

Often times, the 4th horn was often also doubling 1st horn, one octave lower. This would also eliminate one "part".

And so on.

Now, for "parallel octaves":

Remember that for octaves (or any interval) to be "parallel", there must be two in a row, not just a single doubling at the octave.

Take a simple example: two chords, C major, and G major.

To set these two chords in 4 parts, you WILL have to double at least one note of each chord, as they are both triads (3-note chords).

When writing in 4 parts you avoid having the same chord part (fundamental, median or 5th) be doubled in the same voice.

So let's say that you were to double the fundamental of each chord (C and G, in this case), you would have to make sure that the same voice did not get each doubled fundamental. If your Soprano part played "C - G" then no other SINGLE part could also play those two notes in succession.

Let's say the Tenor gets the C doubling... well, then another voice has to get the subsequant G.

I know this went on for a while and may have rambled a bit, but I hope some of it was clear enough and answered your question.

QC's answer is pretty comprehensive and complete, but let me just approach it a different way:

Are you trying to write with traditional harmonies? You can make an 8-note chord without any doublings, but it would be far from common practice. Are you trying to avoid parallel octaves/fifths because you want that polyphonic sound, or just because you've always been told they were egregious? Like Qc said with the example of the strings, you can have one voice always double the bass an octave lower if that's a sound you want to achieve.

So I guess the answer to your question is: it depends on what sound you're trying to get.

Interesting topic (since I am currently writing an 8 part choral, but I didn't have any formal study about this)

Parallel movements of Unison, 5th and 8ve in the common practice period is utilized to have independence of each part. Composers avoided to use it because they are considered as the most related note of a scale---the overtone series.

I think Dev is right, it depends on the sound you want to achieve..

Well, even I have questions regarding this matter.. How 'bout the use of suspended 2nd & 4th? Is there any rule to be followed, I mean aside from the preparation and resolution?

By the way, welcome to YC Rodin ;)

Thanks, guys.

Qc answered my question pretty sufficiently. I was confused because, although 8-part writing is really just 4-part writing doubled in octaves, I've still heard that there shouldn't be parallel octaves between the highest voice and any other voice.

My question does pertains to "traditional" polyphonic writing, although I may not choose to utilize it in some situations.

James, the only "rule" (and I sue the term rather freely here) about suspensions, is that you avoid using the resolution of the suspension in another voice DURING the suspension.

For example, if you have I(6/4) - V - I, where the tonic of the first chord will be a 4th suspension into the dominant chord, resolving down onto the mediant, then you should avoid playing that resolution note while the suspension is still active.

The reason is simple: hearing both the suspension and its resolution simultaneously diminishes the effect of "dissonance" which the suspension is there to create. In this particular example, the tonic suspension is supposed to create tension against the 5th of the dominant chord which follows, before it finally resolves down to the dominant's mediant.

I thought no one want to help me about this :(, but thank you very much Mr. QcCowboy, I really appreciate your help.

Hi have written a song and need an 8 part harmony for it. I do not read music so who  would be best to get the song to for this service.