Quartertones, eighthtones and microtones on the oboe

General observations
The oboe was not developed to play anything smaller than semi-tones. During the 19th century, when most of the mechanical development took place on the instrument it was never envisaged that anything less than a semitone would be required!
This is a vital piece of information for the composer to grasp as there is going to be a certain amount of compromise with what can be done on the instrument.
This in no way means that the oboe cannot produce convincing microtones but that there are going to be some problems that the composer should be aware of before starting out.

There are two ways of producing microtonal pitches on the instrument; the oboist can either lip a standard pitch up or down or he can use fingerings. I suggest that the best results can be obtained by fingering rather than using the lip.

The advantage from the oboist’s point of view of the lip technique is that standard fingerings are used and the pitch is altered simply by changing the embouchure pressure; which means that there are no fingerings to learn. The disadvantage is that it can be a very approximate way of performing and will tend, especially in legato sections, to include slides from pitch to pitch as the embouchure is moved.

The advantage of fingering is that the performer can be much more precise in the production of pitches. The disadvantage is that the performer has to learn a significant number of new fingerings, some of which are very cumbersome, and require a great deal of practice to master.
It has been said that a performer cannot play quartertone fingerings at any speed—this is not quite the case—but it does take a great deal of dedication to practice complex passages sufficiently to perform at any speed.

Something of my own journey in learning and performing fingerings at speed can be found in my article A Discussion of Practices Used in Learning Complex Music with Specific Reference to Roger Redgate’s Ausgangspunkte in Contemporary Music Review, Volume 26 Number 2 April 2007 (Routledge). There is also a recording of Ausgangspunkte on Oboe +: Berio and Beyond on the Oboe Classics Label.

There is no reason why a performer cannot use a combination of lip and fingering. In fact, in order to get pitches in tune the performer will be making adjustments to the embouchure as a matter of course.

The working range is open to discussion:
I suggest that the bottom E1/4b on the oboe should be considered the lowest fingered pitch from which microtones can be developed. Some of the literature does give lower fingerings but I personally have found them unusable, however, you can certainly lip pitches below this range though the accuracy of the pitch is difficult to predict. Quartertones and 1/8th tones can be written over the entire length of the instrument’s range. I have fingerings up to C7 (5 lines above the stave). Though I suggest that the uppermost pitches should only be used if you are very confident that your player is able to get them!

Lists of fingerings are available in the following books:
Libby van Cleve; Oboe Unbound
Veal/Mahnkopf: The Techniques of Oboe Playing (Which also gives fingerings for 1/8th tones)

Composers are experimenting with a wide range of different microtonal tunings—the most common is of course the ¼ tone scale (24 division). It should be remembered that any microtonal writing for the instrument is going to be problematic and the more complex the scale system the more demanding it is going to be for the player.

As well as using ¼ tones, 1/8 tones and 1/6 tones it is also possible to microtonally inflect pitches—to give a sense of the pitch being a little sharp or flat—this can be done anywhere on the instrument (at the bottom of the range it will have to be achieved by using the lip). Equally, pitches can be ‘bent’ by using the lip—they will tend to get a little louder when this technique is used.

It should be noted that while microtones can be performed on any instruments in the oboe family, a performer will almost certainly have to learn some different fingerings for the other instruments—this is because of the difference in the design of the keywork on the larger instruments.

A number of points should be taken into consideration when writing ¼ tones. First, the timbre can be quite different from the standard sound of the instrument—some are darker and some are brighter. Second, some dynamic differences can occur on the ¼ tones. Both of these issues can significantly alter a melodic line as the timber and the dynamics can vary from note to note. Think in terms of natural horns in the classical period and the colour changes when notes have to be stopped. Some composers love this of course! Sometimes it is possible to change the timbre of the standard pitches in order to ‘cover’ the colour changes.

As a general rule when writing microtones for the oboe try, where possible, to work with a performer and, if possible, with the performer for whom you are writing.