In harmony class one is taught not to use parallel perfect intervals as it undermines the independence of the voices. I have come to completely understand this and see why it is so important but when working with entire scores and lots of "voices" how do composers and arrangers stick by this rule?

Of course if you are doubling voices like a melody or bass part, each voice is no longer independent and this is done as a textural effect or to bring out melodic lines by doubling them at the octave etc. But are there other instances where parallel perfect intervals or other voice leading rules no longer matter and it is just about "filling out" the rest of the harmoni spectrum?

For example, I am currently working on a song where I started out with 4 part harmony and the texture is rather low. For the chorus of the song I want to include a piano part or guitar chops in the 5th octave to fill out the high end of the frequency spectrum and create more energy. I believe in the orchestra they call this "tutti" where everyone kind of joins in. How would a classical composer/ orchestrator have done this?

Would the higher piano chords (or higher woodwinds etc) be part of the voice leading in the sense that the lines would have to still have good voice leading. How is this possible? If you have 10 lines or more in the score are only some of those considered as part of the voice leading and the rest just given place in the various registers as "doubled" notes or did the classical composers treat each and every single line independently?

I find it hard to imagine how one might voice that higher piano part while still keeping all the voice leading rules in place. Maybe since the piano part is just part of the accompaniment it doesnt really matter if there are parallel 5ths or if there is parallel motion with the bass line. Or maybe not. Maybe those extra chords I want to use in the chorus still would sound much better adhering to some of the voice leading principles laid out in 4-part harmony. So which is it?

  • 3
    Real compositions do not need to strictly adhere to the rules of 4 part harmony.
    – Lazy
    Feb 25, 2023 at 15:54
  • You call it a song. Are you wanting to orchestrate it the way a classical composer might have? Anyone in particular? Have you looked at any scores? Which ones? Feb 25, 2023 at 16:10
  • Old Yes, It is a song and all I am trying to figure for now is when you have a score with a whole orchestra playing with a string section, woodwinds and brass and all the other instruments, how many of those are actual independent voices and which ones arent independent? I have looked at some scores but if you have any famous ones that might be helpful then please post a reply.
    – user35708
    Feb 25, 2023 at 18:53

2 Answers 2


A full orchestra playing usually has lots of doubling, especially a classical or early romantic symphony. Basically, a classical symphony is often written as four-part harmony, following the “rules” of the style, and the different instruments enter and exit playing one of the four parts to change the tone color.

That’s over-simplified, but in many ways, orchestration is less complicated than it might seem.

One interesting example of how orchestration can sound more complex than it is would be the final “chord” of Beethoven’s ninth symphony, which is simply every instrument in the orchestra playing a D.

Using a piano and a guitar complicates things, and you probably want to understand four part voice leading while also not exactly adhering to it. One way to understand voice leading for more lines is to review literature with more independent voices.

I’ve started using Pictures at an Exhibition as a model because there is the original piano version and it has a lot of chorale-style voice leading but with “big” chords and “newer” harmonic ideas compared to the classical period (e.g., “Promenade” ends with ii V I). Comparing the piano with the orchestration really helps me understand the relationships between the voices and how the doubles are split out.

Also keep in mind that the “rules” from harmony class are actually just practices of the specific era - they don’t by themselves tell us what will always sound bad or always sound good. The mid and late romantic period saw the use of many parallel perfect intervals, but not randomly. Specific voice leading that uses the sound of parallel perfect intervals for certain effects were developed. So you can use parallel perfect intervals, but if you’re not sure how or why you’re using them, you might not end up with the desired sound.

If you’re trying to understand how classical symphonies were composed, you would do well to go right to the source. All the scores for the European composers of the 18th and 19th centuries are available free on imslp.org. Pick your favorite work, get the score, and start analyzing. There are also piano reductions for many works that you can get to be able to more easily see the parts, lines, and harmony.

  • Thanks Todd, will check out that link. The way I see it is that parallel perfect intervals are fine if you dont care about independence of the lines so if you dont care about that then thats when you can use them. In an accompaniment you I don't really hear voices or different lines which is why most songwriters that actually studied counterpoint say the bassline and ,melody is where you want to stick to counterpont rules as much as possible, the rest kind of just fills in the harmonic spectrum. That is with modern music however and I was curious about orchestras to see how they did it then.
    – user35708
    Feb 25, 2023 at 19:04

If you are writing 4-voice harmony in the 17th century style, parallel perfect intervals are prohibited.

In other styles they are permitted, even exploited. Just be aware of how their type of ultra-similar motion sounds. Here is my favourite example of (largely) 4-part harmony infested with parallel 5ths. It's lovely. But beware of doing it by mistake in the middle of a piece otherwise in 'Bach chorale' style.

But you asked about orchestration. If writing a section of block harmony in a style where parallels are frowned upon, the rules still apply. But don't confuse parallel octaves within the harmonic texture with octave doubling between different instruments. That's completely allowed. And, as you say, when dealing with a 'song' - melody, bass line and fill-in chords - all rules are off.

"I was curious about orchestras to see how they did it then."

Shame on you! Go to IMSLP and find out!


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