Writing for vocal ensembles
Vocal ensembles
For convenience, it is common to abbreviate voice types to their first letter or syllable; therefore: S=Soprano; A=Alto; T=Tenor; B=Bass; Bar=Baritone; Tr=Treble.
Mixed choir (SATB)
The most commonly found mixed choir is that consisting of soprano, alto, tenor and bass. With a mixture of male and female singers, this combination offers the greatest range and variety of tone colour of any vocal group, and is also specialised to sing four-part harmony. Because there is usually more than one singer to a part, the voices can be and frequently are divided at some point in the music. Sometimes the divisi is marked enough that the composer may specify the choir as being in five or more parts, as happens, for example, in J.S. Bach's Magnificat in D, which calls for two soprano parts to form an SSATB choir. SATTB is another fairly common combination. There is no limit to the number of sub-sections the four main voice types can be divided into, although very large combinations will of course require a greater number of singers.
Male choir (TrATB)
Essentially an antique prototype for the mixed choir described above, the soprano and alto parts are replaced by boy trebles and counter-tenors (male altos singing falsetto). This ensemble is still found regularly in the British cathedral tradition, although it is worth noting that many cathedral choirs are starting to accept girl choristers as well.
Double choir (SATBSATB or SSAATTBB)
From the Renaissance to the present day, the standard mixed choir in a sacred setting has often been physically divided into two to maximise the effect of antiphonal music sung in churches and other spaces. Sometimes, however, the need has arisen for there to be two (or indeed more) separate choirs in a score. The reasons for this may be technical (Bach had a small group of professional choristers and a larger choir of amateurs of varying ability at his disposal), acoustic (spatial effects such as mentioned above in the music of composers such as Monteverdi) or just practical (a bitonal piece will be easier for two choirs to sing, one in each key). In the Bach example, namely the St Matthew Passion, the less experienced singers are used in a pragmatic way; they represent variously the crowd condemning Jesus and the church congregation. The double choir need not always be used as two separate units; in Purcell's seminal Hear My Prayer and Tallis' Spem in Alium, all eight/forty voices weave together in the overall texture.
Choir with soloist
A choral work may feature one or more soloists either for part or the entirety of its length. In the former case, the director of an a capella group will decide whether to position the soloist in front of or in the main body of the ensemble.
Other groups
Male- or female-only voice groups are common amongst amateur singers and much music has been written or arranged for such groups. The Welsh male voice choir (TTBB) is a venerable tradition and a source of national pride, particularly when performing hymns in the vernacular language. The barber-shop quartet (TTBarB), with only one voice to a part in close harmony, is a highly adaptable ensemble that has remained popular from the beginning of the twentieth century. Female choirs (SSA, SAA or SSAA) and children's choirs (often singing in unison with piano accompaniment) are also widespread amongst amateurs, with some amount of music written specifically for these ensembles.
Scoring considerations
Breathing
Like orchestral wind and brass players, singers need sufficient time to breathe. As much of the history of Western music is the history of vocal music, it is interesting to note that a standard melodic phrase in almost all music corresponds to the length of phrase a singer can comfortably perform in one breath. It is vitally important to the success of vocal music that the performers are able to breathe comfortably and without disrupting the flow of the music. In ensembles it is particularly important not to stretch the singer's capability because of the importance of performing together, unlike a soloist who has more freedom of speed and phrasing. As with many aspects of vocal writing, the best approach is for the composer to sing through the part themselves to check its suitability. Do the singers have enough time to take the breath? Will more air be need for a more taxing passage? Another consideration is that in more extended pieces a section will appreciate a slightly longer rest of a few bars or more to maintain their stamina.
Word-setting
Rhythm
Any vocal composition process should commence with a careful study of the text. The composer must consider, amongst other things, how the rhythm of the syllables can be best translated into music. The subject of the text itself may suggest some aspect of this - for example, a poem about the sea could be effective set to the rhythm of a sea-shanty. Another important consideration is the language of the text, which will greatly affect rhythm. Some composers, notably Leos Janacek, devoted a great deal of effort in recording the speech-rhythms of their native languages, to the extent that it became an important part of their overall musical style. Whatever language the text is in, even if is your own, care must be taken that all syllables are set appropriately. Certain syllables will be impossible to sing on very short notes, or in dotted rhythms, whilst others may be lengthened over melismas with great effect. Speaking the text in the rhythm one is considering is a useful way of determining whether it is appropriate or not.
Strong and weak beats
A related concern to the above is understanding the stress patterns of the words and matching them to the strong and weak beats of the music. Again this may well vary widely amongst different languages. Some languages stress the first syllable almost without exception; others, like English, are more free in this aspect. In his Symphony of Psalms, for example, Stravinsky places the strongest syllable in the phrase Lau-da-te DOM-i-num on the first beat of a bar, with a written accent. Again, 'speaking' through the text in rhythm will help in this process.
Vowel sounds and range
Singers will always sustain the vowel sound of a syllable on any note, as it is far more natural and practical than trying to sustain a consonant. One must be careful, therefore, that the shape of the lips and vocal chords for the vowel sound is also suitable for the part of the singers' range required. Any 'i' sound, for which the vocal chords must be tightened, will not be successful if the note on which it is sung is in a very high register. However, an 'a' sound, in which the mouth is open and the vocal chords relaxed, would be. In fact, an 'i', as in the word 'In', is a rather awkward vowel to sustain anyway, and the sound may often be performed 'ee' to produce a better tone, which goes some way to eliminating the problem.
Pitching and voice-leading
Unlike the majority of instrumentalists, singers have no mechanical way of finding their notes, and must 'hear' the pitch they are preparing to sing by listening to other notes around them or relating it to their previous note. This may go some way to explaining why almost no music in the 12-tone method has been written for choir; because this system obviously lacks tonality, there is no secure reference notes for the singers to use to find subsequent pitches. Luckily, both amateur and professional singers can find even quite difficult intervals provided the composer makes provisions to assist them. If the passage is reasonably diatonic then the intervals between pitches can be found with ease, either by referencing the previous note, or, in the case of an entry after a rest, by listening to pitches in other parts (including any accompaniment). This also holds true to some extent for chromatic intervals, however if the tonal centre (if there is one) moves unexpectedly it can be very difficult to gain a pitch reference. It is thus inadvisable to place wide skips in chromatic passages, and to approach complex chords step-wise. This approach will also assist singers in harmonically simpler music. Contemporary music has however, pushed the envelope of what can be achieved with voices, and provided the composer consults a capable singer, highly complex parts may still be successful.
Voice-leading should, if possible be studied systematically, for it is an integral part of learning to compose for music. Generally speaking, major fourths, perfect fifths, major and minor seconds, major and minor thirds and octaves are the easiest intervals to find. Sixths and sevenths are slightly harder (except the cadential seventh) and other chromatic intervals the hardest of all. We also do not recommend writing intervals of over an octave, especially for amateur groups. Neither are successive chromatic intervals within a small range (ie alternating major and minor seconds) easily executed.
Accompaniment
Accompaniment for vocal ensembles can range from a single piano to an full symphony orchestra. It fulfils any of three primary functions:
- - To provide pitch support
- - To thicken the sound and play in ranges which are not possible for the singers
- - To provide textures and effects not achievable by the voices
The first is the most common, with the choral parts being doubled exactly by the accompanying instrument(s) or at the octave. Indeed, the string instruments of an orchestra corresponds rather neatly with the ranges of the four principal voice types (the contrabass doubling the cello an octave down) and in much choral music from the common practice period the string parts are almost identical to the choir parts. The second use may apply more if the choral ensemble is of a limited voice type (such as an all-female choir which would lack a true bass range) but is still worth considering in scores calling for a full choir. If the choir has a passage of singing in unison, the accompanying parts may be used to provide the rest of the harmony altogether.
Whatever accompaniment is used, care must be taken that the volume or texture do not swamp the singers, who are unable to compete at very high volumes.
The speech choir
We have not so far mentioned a type of choral writing developed by some composers in the mid-twentieth century, that for 'speech choir'. Instead of singing actual pitches, the ensemble may variously recite the text, speak it in a rough tonal shape, or use extended techniques such as body percussion, shouts, breathing noises and other vocal effects, as well as aleatoric and other unorthodox compositional techniques. Xenakis and Rautavaara are two composers who have contributed to this genre, which can of course be used in conjunction with more conventional choral writing.
General Advice
- Whilst heavily divided chords can sound variously luscious, luminous and powerful, care must be taken with their employment. All chords, particularly chromatic ones, should be approached in a way that is as easy as possible for the singers to pitch. Another important point from instrumental orchestration is to put wider intervals in the bass to avoid the chord sounding muddy - unless this is your desired effect. If complex chords are divided ad libitum, the director may have to assign individual members of the ensemble to each pitch to ensure the chord is satisfactorily balanced. Finally, such devices should be used carefully to maximise their effect and should be contrasted with more lightly scored passages or contrapuntal textures.
- Avoid extremes of register. Whilst, for example, a few of your basses may be able to hold a bottom D, others will physically be unable to sing the note. We would strongly recommend staying within the 'normal' vocal ranges to ensure the security of the ensemble. If you must write very low or high notes, it would be a good idea to provide an ossia note for those that cannot reach it or are unreliable.
- Word-painting is a valuable device that has been used throughout the history of vocal and choral music. Even today, there are still many original and interesting ways of illustrating the text musically.
- Select and study the text carefully. Consider its structure, mood, tone, rhythm (is it in a particular meter?), any opportunities for word-painting and other salient features.
