There are five sections in the string orchestra, playing five parts, but quite often we need more than five notes at once. There are two ways to get the extra notes, use double stops or divide sections, divisi. In 90% of situations you should choose to divide. There are issues with double stops that I will explain in the next article.
So how does the string section divide?
The default behavior is to divide on the stand. This is also called ‘inside/outside’ as the outside player (closest to audience) takes the top note and the inside player takes the bottom. Some section leaders may instruct the section in other ways, but this is what I have found to be the default, so if you want something else, (e.g., front and back), you should mark it. No discussion is needed for a simple two way divisi.
If you need to go into more parts, say div. a3, that is when a discussion is needed. The leader will work out a plan and let people know. Just keep in mind that the more you divide, like into five or seven, the more complicated it gets and the more time is wasted with discussions. You also increase the odds that someone will misunderstand what part they should play. As mentioned previously, I don’t mark it when the split is two way. But I do mark it when the division involves three or more parts so the leader will see it BEFORE the section plays and can work out a plan.
One thing unique to film scoring is that we copy first and second violins on the same part. This allows us to easily change the the weighting. Need more people on the melody? No problem, just tell some or all of the seconds to play that line. Also, this allows us to do divisi across the whole group. For example, a three-way division of all violins is very easy to notate when they all see the same parts.
What section do you divide when you need more than five string voices? Range has a lot to do with it, but let’s say we need an extra note in the upper range. In that case divide the second violins. Leave the firsts on one note. A lot of the impression of the size of the orchestra comes from this top part; split it and you change that perception. There are some great colors to be had by dividing the firsts, but if all you want is to add an extra note without affecting the sound, leave the firsts alone. You can also divide violas with no problems. If the extra note is needed in the lower range then divide the celli. Due to the size and weight of the cello, it can easily divide without changing the weight of the sound. If you need root, fifth, and tenth down low, basses would take the root and celli the next the notes. Basses are too thick sounding to divide into anything other than octaves. If you are searching out interesting colors then go ahead and divide in other ways, div a3 or a4. The above rules are designed to maintain the full sound of the string section, not to be overly artistic!