For most things music, rules are made to be broken. So from now on let’s instead call these guidelines instead of rules. We’ll start by defining exactly what a “mixed” ensemble is.
A mixed ensemble is any ensemble of instruments from different instrument families.
Some examples of mixed ensembles are: orchestras, wind ensembles, marching bands, Pierrot ensembles, and chamber groups.
Here are some guidelines to follow when writing for a mixed ensemble:
Not all instruments are created equal! The differences in the dynamic range in a ensemble will make or break certain voicings. For instance, a trumpet and flute have very different dynamic possibilities when performing a G5.
Group like instruments. This isn’t a hard and fast rule, however, instruments of the same family typically work well together and can be grouped in close proximity in a chord. Two clarinets playing a third will be easier to blend than a trumpet and a clarinet playing a third.
Double with caution! Whenever working with an ensemble of more than three instruments doubling becomes a necessity. Traditional music theory teaches us to be careful about doubling certain notes in a chord, but care should also be taken when having different instruments doubling the same note. An oboe and trumpet playing a unison note will sound very different than a flute and trumpet.
Don’t be afraid to get creative! Experimenting isn’t only ok, it’s encouraged. If you decide you don’t like something, it can always be changed.
Below are some possible ways to orchestrate a hymn for a Pierrot ensemble.