Iacobus Leodiensis [Iacobus de Montibus, Iacobus de Oudenaerde]

2. History to 1600.

After the breakdown of Greco-Roman civilization, music in western Europe was preserved by rote memory, and new music was presumably worked out in performance or created spontaneously in improvisation. Since our knowledge of this music is limited to traditional liturgical chants written down in imprecise notation long after they were created, it is difficult to draw concrete conclusions about any improvisatory techniques used in their creation. The most reliable extant evidence relates to the spontaneous improvisation of the Jubilus, a melismatic flourish found on the last syllable of certain alleluias preserved in the early Christian liturgy. Clear references to this type of improvisation appear in the writings of the early Christian Fathers. St Augustine (354–430) described this jubilus as the musical outpouring of ‘a certain sense of joy without words … the expression of a mind poured forth in joy’. In its melismatic, virtuoso style it is not unlike the vocal cadenza added centuries later at the cadence of a Baroque aria.

A second, more controlled, improvisatory technique is hinted at in the structure of a number of surviving chant melodies. The chants in a particular mode, such as the Dorian, often use the same, or a similar, vocabulary of melodic motifs. This is taken as indicating an improvisatory practice in which the modes, like the rāga of India, included thematic materials as well as a roster of notes in their identities.

(i) Ensemble improvisation.

(ii) Ornamentation.

(iii) Improvisation on ‘perfect instruments’.

Improvisation, §II, 2: Western art music: History to 1600

(i) Ensemble improvisation.

Although melodic improvisation remained a factor in Western culture, it is indicative of its later development that the earliest substantial information about improvisation appears in treatises instructing the singer how to add another line to a liturgical chant as it was being performed. This is no doubt due to the fact that, although this early organum may have been derived from folk practice, the problem of improvising a melody to fit with a given chant required a technical knowledge of vertical consonance and dissonance and of the melodic materials available in the diatonic system. Furthermore, while at first the improvising singer may have relied on his memory of the chant to which he was adding a counter-melody, the improvisers eventually saw this chant in some sort of visual notation so that they could anticipate its notes. Thus the first manuals on improvisation are those concerned with the beginning of contrapuntal theory and practice and with the development of mensural staff notation.

Starting in the 9th century with the anonymous Musica enchiriadis and Scolica enchiriadis, which tell how to double a chant at the perfect intervals and to make oblique motion at the beginning and end of the chant, there was a steady growth and refining of the technique of organum. By the 11th century, when Guido of Arezzo described in his Micrologus the use of contrary motion and of rudimentary cadence formulae, there are also, in one of the Winchester tropers, a number of two-voice organa written down in staffless neumes that apparently use these same devices. From this time on, many written-down organa are found outside theoretical treatises, but the precise relation of these to improvised style is not defined. Two- and three-voice organa which introduce the use of several notes against one in the cantus firmus, such as those found in 12th-century manuscripts at St Martial, Limoges, and Santiago de Compostela, have the appearance of written-down improvisations, and it is unlikely that a composition was yet worked out by writing it down. Musical forms of the 13th century – discant, organum, motet etc. – were created by adding one line at a time to a previously worked-out melody, each of the added lines agreeing with this melody but not necessarily with each other. The interrelation of the parts was the same as when two singers improvised on a cantus firmus. By the 14th century, when a precise visual notation for music was established, complex structures, such as the isorhythmic motet, that could be worked out only by being written down, had also developed. Thenceforward the dependence on notation for composing music as well as for preserving it became one of the distinguishing features of Western musical culture, and in due course composed music, precisely notated, became the primary basis for performance.

Improvised music, however, remained an important element in art music for several centuries, and the interaction of the two types was fruitful. A well-known instance of the influence of improvised style on composed music is the introduction of the fauxbourdon style into the music of Burgundian composers, such as Du Fay and Binchois, in the 15th century. In Britain in the late 14th and early 15th centuries, the practice of improvising above a ‘sighted’ chant took the forms of parallel 3rds (gymel) and parallel 3rds and 6ths together (English discant). Although scholars still differ as to the exact historical process and the meanings of certain terms, the musical effect of these techniques on styles of composition is clear. In Britain this resulted in compositions that were structurally based on a series of 3rds or 6-3 chords that were freely ornamented and sometimes interspersed with other combinations of intervals. In Burgundian music, sections of parallel 6-3 chords (fauxbourdon) are inserted into the common styles and are found frequently at cadence points.

It was also in the 15th century that theorists of counterpoint first made a distinction between improvised and written-down styles. In 1412 Prosdocimus de Beldemandis simply mentioned the existence of two types of counterpoint – the ‘sung’ or ‘performed’ and the written – but in 1477 Tinctoris clearly spelt out the difference between the two in his Liber de arte contrapuncti. Because each improviser could make his line agree with the cantus firmus alone, dissonances and awkward part-writing could not be avoided. Moreover, an improvised piece was looser in construction, whereas the composer could order such features as cadences and rhythmic motion, thus producing a finished work (res facta) with a distinctive character.

The difference between the two styles became even greater in the 16th century, when composition on a cantus firmus became less a normative and more a specialized technique. Composed works appeared in a number of new styles and forms, while singers still improvised over a cantus firmus in long notes, often repeating a single figure as long as it fitted. At this period, improvisation was widely practised in Italian churches, where it was normally used over the chants of the introits in the Proper of the Mass, as well as over the hymns, antiphons and graduals. Since motets and the Ordinary of the Mass were set as artfully worked-out compositions, listeners will have apprehended two distinct usages.

It was not until 1553, when Vicente Lusitano’s Introdutione facilissima was published, that a methodical procedure for learning to improvise on a cantus firmus was made available. His ‘secrets’ seem very simple, as he was presenting a basic method by which the technique could be learnt; it may well have been based on his own way of improvising. He first gave a number of mechanical patterns in long notes that fit over the different intervals found in plainchant, such as those in ex.1a, where the syncopated line makes a series of 3rds, 5ths and 6ths over a succession of horizontal 3rds in the cantus firmus. Once the basic pattern was learnt, the singer could fill in the long notes with florid passages. Lusitano also included a number of single melodies in florid counterpoint above a cantus firmus (ex.1b). This exemplifies another of his suggestions: if a passage will fit more than once, the singer should continue to use it. He gave a number of florid examples above the same cantus firmus, and when two of these are combined, as they would be in performance, a number of dissonances and parallel 5ths appear between them.

Two years after Lusitano’s treatise appeared, Nicola Vicentino, in L’antica musica ridotta alla moderna prattica, condemned these devices as old-fashioned and recommended more modern ways, such as having the imitating voices imitate each other rather than the cantus firmus. Zarlino, in the third edition of his Istitutioni harmoniche (1573), gave, for the first time, instructions for more sophisticated devices, such as the improvisation of strict two-voice canons on a cantus firmus and two- and three-part canons without a cantus firmus. These techniques signalled a great change in improvised counterpoint. Both require more technical skill on the part of the performers. The leading singer must know all the possible combinations at specific times over precise pitches, and those following him must have good ears and memories. But this kind of planning also makes correct part-writing and dissonance treatment possible in improvisation. Zarlino also introduced rules for creating invertible counterpoint and for adding a third part in the performance of an already composed duet. During the last quarter of the 16th century his successors expanded the possibilities inherent in these new devices and also continued with the old. The art of improvised vocal counterpoint came to a final climax among the theorists and practitioners of counterpoint in the prima pratica style.

Although there are many early visual and literary references to instrumental ensemble music, no direct discussion of improvisation by instrumental groups has been found. We can only surmise that when contrapuntal – as opposed to heterophonic – improvisation took place in instrumental performance it was by players who had been trained in the vocal practice of improvising on a cantus firmus. The first sure evidence of such a practice is in the improvisation of the music for the bassadanza and saltarello danced in 15th-century Italy. Surviving collections of bassadanza tenors in long notes, along with pictures showing two high instruments presumably improvising on a tenor played by a sackbut, indicate that the music accompanying these dances may well have been produced by just such an improvising group. Later compositions on one of these bassadanza tenors, La Spagna, in which the tenor in long, even notes is accompanied by florid melodies in the upper parts, add weight to this conclusion.

It is significant too that the only book in this period giving examples of ensemble improvisation (for violone and harpsichord), Diego Ortiz’s Trattado de glosas (1553), still used the old La Spagna tenor when illustrating the technique of improvising on a cantus firmus. The beginning of one such improvisation (ex.2a), when contrasted with another (ex.2b) from the same book, shows the archaic nature of this improvisation. The one shown in ex.2b has a 16th-century Italian dance bass, which acts as a series of roots for triads, and the improvised melody is shaped by the notes of each chord and is organized motivically. The bass also gives the rhythm of the dance and is organized in phrases that are multiples of four bars. It is also short and is repeated several times, showing a series of improvised variations – a form and style that were to be used in improvisation for several centuries to come.

Improvisation, §II, 2: Western art music: History to 1600