There are two important aspects to auxiliary wind instruments that are interrelated, yet off the radar of many orchestrators. They are:
- Sometimes, it’s better that a player stays on their auxiliary instead of changing back to their principal instrument, and…
- Auxiliary instruments are useful as part of the general fabric of a composition, not just as soloists or as extensions of their sections.
Let’s say that you’re second oboist for a mid-sized orchestra. You play a lot of cor anglais parts as a result. On one new work, you’re piping away at some very good writing for second oboe – clean, well-supported, and easy to articulate. Then you’ve got a little solo on cor anglais a few bars later, followed by a quick change back to oboe II for a few background notes. Then you’ve got to play that solo again, and then trade of back and forth several times over the next few minutes.
What’s the main thing you want to tell the composer at that point? “Why can’t the cor anglais play those background notes?” For indeed, the cor anglais is a most flexible instrument. And yet it’s hard for composers to realize that it’s a great supporting instrument, capable of very soft playing, and a range that’s in some ways more even throughout its registers than its prototype, the standard oboe.
The same applies for piccolo. Many are the passages in which a composer has carelessly scored a bunch of changes back and forth between second flute and piccolo, unnecessarily if all the passages are in the same basic octave above the staff in concert pitch. As long as the dynamics are handled intelligently and there aren’t too many loud notes below written D in the staff, there’s no reason why a player mightn’t just play right through the whole passage on the piccolo. The instrument can add a pearly color to support textures, or merge seamlessly into the background with upper strings or unison with flute I.
Of course, there are exceptions to this, especially with instruments of an octave extension downward, like the contrabassoon. In this case, the rougher buzzing of its immense reed gives it away in higher passages, making it hard to blend as naturally with the standard bassoon. But the same isn’t true for the bass clarinet, whose paler upper register is enormously useful in support scoring. It can fill in a midrange harmony along with a regular B-flat or A clarinet, or eerily track the flutes at one or two octaves, or thicken the viola line. It doesn’t have to just bounce creepily around in the basement.
The above sample depicts a passage in which the composer wants a featured bass clarinet solo in its bottom register. Halfway through the passage, the top version asks the player to put down his instrument and pick up his clarinet, playing some chalumeau register harmonies with the wind section. Then it’s back to bass clarinet again for some more spelunking. But as you can see in the lower version, there’s no need for such a change. The player can stay on bass clarinet for the whole passage. There’ll be virtually no difference to the listener.
The implications go further than merely the fussiness of constantly alternating between two instruments and two different types of reading. There’s also the issue of instrument temperature. A player is going to want to hold onto their instrument for as long as possible once it’s warmed up. Think about that next time you hear an E-flat clarinet or cor anglais entrance that’s a little flat. Don’t always blame the player: the temperature of the hall and lack of planning by the orchestrator may be factors as well. Yes, you can actually write a part into your piece where you’ve created a risk of sounding off, or at least less than perfect intonation. Keeping instrument changes to a minimum can be key to lessening this risk, and realizing that auxiliaries can cover certain parts can be liberating in this process.