How to Arrange 4-Part Harmony for Strings

In this tutorial we’re going to look at six different ways to adapt four-part harmony to a string orchestra.

Four-part harmony is a traditional way of harmonizing a melody for four “voices” (either literal human voices, or instruments). Many introductory harmony courses teach four-part writing because it is a straightforward method for learning chord voicing, good part motion, and proper treatment of dissonances.

Although some critics think four-part harmony is old-fashioned and academic, I’m going to show you that there are still practical uses for four-part writing. Contemporary arrangements and scores use variations of these techniques all the time.

As just on example of contemporary use, John Williams’ “Anakin’s Theme” from Star Wars Phantom Menace uses four-part harmonization techniques in both the introduction and the main theme:https://www.youtube.com/embed/OLQ-rCSbFeQ

(Because this tutorial is a bit notation heavy , I’ll include screenshots from Logic for the more DAW oriented readers among you.)

A Typical String Section

A standard string orchestra is based on the string quartet; Violin I, Violin II, Viola, and Cellos, with the addition of Contrabasses on the low end.

A string arranging technique we’ll be using a lot here is divisi, which is dividing a section of the strings into multiple parts. If the viola is divisi in two parts, for example, half of the violas will play the top part and the other half will play the bottom.

Naturally there is a slight loss of power when a part is divisi because less players are playing each note. However the difference is in no way half (two violas are not literally twice as loud as one), and from a full string orchestra a divisi part can still give a very rich and full sound.

Basses are rarely written divisi, and will not be at all in the examples in this tutorial.

4 Voices

For all of the arrangement variations, we’ll use a typical Bach chorale in four part harmony.

The most basic arrangement is to simply assign the four parts from lowest to highest down the instruments of the string orchestra. So the soprano goes to Violin I, alto to Violin II, etc. In this case we won’t use the contrabasses.

As long as you’re part-writing is solid and your ranges are on the instruments, this is pretty much guaranteed to sound good.

• Vln I – soprano
• Vln II – alto
• Vla – tenor
• Vlc – bass

5 Voices – Filler

Strings sound particularly resonant and full when there are few gaps between the different parts. For that reason it can often be a good idea to write a fifth part, a “filler” that fills in some of the space in the middle.

To create the filler you don’t need to worry so much about the rules of four-part writing because that has already been taken care of with the other parts. Our objective here is big thick harmony, not pure counterpoint.

The filler is also definitely more felt than heard. The new line will borrow a little from each part, filling in a chord tone here and a chord tone there, and is really just a subtle technique for beefing up the fullness of the strings.

In keeping with our smaller section, we can give the filler part to the violas and have Violin II take both the alto and tenor parts divisi. (Care must be taken that the tenor part does not go lower than the Violin II can play, which in this case it does not.)

• Vln I – soprano
• Vln II – div. alto/tenor
• Vla – filler
• Vlc – bass

Since the filler part is between the alto and tenor, you might be wondering why we don’t just keep going down – Violin II on alto and filler, Viola on tenor.

By having Violin II both above and below the viola, the three parts work as a cohesive unit. The different sounds of the instruments dovetail and blend together, rather than stack and thus slightly sound in contrast. The difference is subtle at best, but it is important to make the strings sound as much like a unified group as possible.

7 Voices – Basses

The next version introduces the basses, which will typically duplicate the cello parts down an octave.

Remember that contrabass parts sound an octave lower than written, so you can write them the exact same way as the cellos and they will sound 8vb.

This arrangement will add a thick bottom which can give you a strong and bold sound. Be aware of the heaviness though, because it is not always appropriate and can sometimes bog things down.

The Violin II and Violas will both play divisi with the alto part in the top of each.

• Vln I – soprano
• Vln II – div. alto/filler
• Vla – div. alto/tenor
• Vlc – Bass
• CB – Bass 8vb

8 Voices – Melody 8va

From here the only place to go is up!

We can divide the first violins by having the melody doubled an octave higher.

To counteract the extra weight on the melody, half of the violas can be used to double the bass. When the bass part is too low and out of the viola’s range (the lowest available note on the viola is C an octave below middle C), you can have it play the next nearest available chord tone.

This arrangement is nice because you get the full resonant harmony of the previous arrangements, but the melody stands out nice and clearly on top.

• Vln I – soprano 8va/soprano
• Vln II – div. alto/tenor
• Vla – div. filler/bass filler
• Vlc – Bass
• CB – Bass 8vb

8 Voices – Top Voices 8va

If you don’t want the melody to stick out on that high octave quite so much, or if you just want to fill in the harmony for a richer sound, you can double your alto and tenor parts up an octave as well.

We’ll keep the first violins playing the melody in octaves, with the higher alto and tenor parts dovetailed in the middle.

If you compare this to our original four part arrangement, basically we have doubled the top three voices up and the bottom voice down. You get a very full and rich arrangement without having to compose an additional note!

• Vln I – soprano 8va/soprano
• Vln II – div. alto 8va/tenor 8va
• Vla – div. alto/tenor
• Vlc – bass
• CB – bass 8vb

9 Voices – Melody 8va & 8vb

A variation on the previous arrangement is to double the three upper parts up an octave, and also to double the soprano part down an octave as well. Given to the cellos, this will create a very rich sound.

This will really only work when your soprano part is a featured melody. If you were trying to use the strings as a background harmonic accompaniment, this version would probably draw too much attention to itself with the high cello melody.

• Vln I – soprano 8va/soprano
• Vln II – div. alto 8va/tenor 8va
• Vla – div. alto/tenor
• Vlc – div. soprano 8vb/bass
• CB – bass 8vb

Conclusion

I’m the first to admit that the differences between many of these options are subtle. The main differences to be aware of are what happens when you start adding octaves below (by adding basses) or above (by doubling in higher octaves).

Different situations will call for different arrangements, but any of the above options could be appropriate at both very quiet and very loud dynamics.

This is just one way to work with strings. There are plenty of other textures including polyphonic and homophonic writing.

Hopefully this tutorial gives you some ideas for how to write a very full and resonant arrangement for string orchestra. Share your thoughts and questions in the comments!