Iacobus Leodiensis [Iacobus de Montibus, Iacobus de Oudenaerde]

(ii) Ornamentation.

A less difficult type of ensemble improvisation occurred in the 16th century when florid passages were added to a single line of a composed work while it was being performed. These ornaments were called diminutions, since they reduced the longer notes of a piece into a number of shorter notes; this practice was also referred to as the ‘breaking’ of a melodic line. Skill in diminutions belonged to the performer rather than to the improvising composer, and it required little theoretical knowledge, since the performer needed only to fit florid patterns into the longer notes of an already composed piece. More care had to be taken by the singer or instrumentalist who embellished the single line of a polyphonic work of which he saw only his own part than by the organist who had a complete work under his control, but the procedures taught by the various published manuals on diminution were designed to help him avoid these difficulties. There were lists of the numerous melodic patterns that fitted into each melodic interval and note length commonly found in music of the time, and these patterns could be transferred directly to the melodic line that the soloist wished to ornament.

Three general procedures were followed in creating these embellishments. The simplest was to have the substitute passage begin and end on the pitch of the notes being ornamented and then move immediately to the next note in the melody, a procedure shown in ex.3a. This was considered the safest, for it preserved the original contrapuntal movement of the work. The second way, shown in ex.3b, was to start on the original note but, instead of ending on it, to move on and arrive at the next note by conjunct motion. Although this way might produce contrapuntal errors such as unauthorized dissonances or parallel 5ths, it was assumed that they would not be noticed by the listener because the notes were so short. The third manner was simply to be freer, perhaps encompassing a longer segment of the original line in the embellishment or replacing one of the main melodic notes with a pattern not touching on it. While it was not approved, this technique can be seen in the ornamented works that are given in the diminution manuals; it often involved motivic or sequential patterns, as seen in ex.3c. It could be successful, however, only if the performer knew what was going on in the other parts.

This type of improvised ornamentation was usually applied to only one voice of a polyphonic work, but when a madrigal or motet was performed by soloists, each improvising diminutions on his part, care was taken to agree in advance the order in which they would add ornaments, to avoid contrapuntal confusion and dissonant clashes that might result from simultaneous ornamentation. Care was also taken by the performer of the bass part not to let his ornaments go above the tenor part and to limit his embellishments, so that the overall structure of the supporting bass line was retained throughout.

The first manual teaching the art of improvising diminutions for a solo singer or wind or string player in ensemble performances of polyphonic works was the Fontegara of Sylvestro di Ganassi, published in Venice in 1535. It is believed, however, that this practice must have appeared early in the development of polyphonic music, since the earliest known keyboard tablature, the Robertsbridge Codex (GB-Lbl Add.28550, c1360), contains elaborately ornamented versions of contemporary motets, and it is generally considered that the published manuals of the 16th century were a late attempt to codify and make available to all musicians the ‘secrets’ of this technique.

Improvised diminutions had a definite influence on composed music, for they introduced elements into the performance of Renaissance music that became an integral part of Baroque style. The ornamentation of a single line of a polyphonic work by a solo instrument while the entire work was played on a keyboard instrument, as seen in the second book of Ortiz’s Trattado de glosas, anticipated the solo instrumental writing of the early Baroque period. In the same manner, the ornamented cantus parts of frottolas such as the anonymous Aime sospiri printed in Petrucci’s sixth book of frottolas (1506), and the embellished top voices of selected four-part madrigals by Rore included in Girolamo dalla Casa’s Il vero modo di diminuir (1584), which were sung while the other parts were played on the lute, were forerunners of early 17th-century monody.

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

(iii) Improvisation on ‘perfect instruments’.

For the Renaissance musician, the ‘perfect instrument’ was one such as the organ or lute, on which a single performer could play all the parts of a polyphonic composition. Starting with the Robertsbridge Codex and the Faenza Codex (I-FZc 117, c1400), elaborately ornamented versions of polyphonic motets and secular works appeared as a constant part of the repertory and can doubtless be seen as written-down examples of a common improvisatory procedure. Highly embellished intabulations of polyphonic vocal works continued to appear in keyboard manuscripts into the 16th century, when, with the development of music printing, a great many such arrangements for lute and vihuela, as well as for keyboard, were published. From the 14th century on, keyboard tablatures also included sacred chants and secular songs used as cantus firmi with florid countermelodies. The fact that a number of 15th-century manuscripts, such as the Fundamentum organisandi (1452) of Conrad Paumann, give practical instructions for adding keyboard-style countermelodies to fit with the intervals commonly found in such pre-existing melodies tends to confirm that contrapuntal improvisation on a chant in church or on a popular song in secular music-making was a common practice with the professional keyboard virtuoso. While these techniques were still important in 16th-century keyboard improvisation, the gradual abandonment of the central cantus firmus and the use of free forms based on fugal imitation in vocal music are reflected in the inclusion of canonic and fugal devices in Hans Buchner’s Fundamentum (c1520) and the Arte de tañer fantasía (1565) of Tomás de Santa María.

A new form, the set of variations on a popular tune or dance bass already familiar to the listener, also became a major element in improvisatory practice in the 16th century. These variations used both the older technique of cantus firmus and the new one mentioned above (see ex.2b), which has a set of chords as the ‘theme’. In some cases both the melody and the harmony of a popular song form the basis of a set of variations. This practice is paralleled in vocal music, where poet-composers, and less sophisticated figures too, improvised both words in fixed forms such as terza rima and ottavas, and vocal embellishments, over standard melodies, such as the romanesca and Ruggiero, and their attendant harmonies.

A special genre associated with the keyboard was the prelude or intonation, a free improvisation meant to establish the mode for a vocal or instrumental piece that followed it. The earliest written-out examples of this type are found in the keyboard tablature of Adam Ileborgh (1448). This genre was characterized from the beginning by idiomatic virtuosity, rhythmic freedom and loose thematic construction – features that listeners have always considered the true hallmarks of extemporaneous improvisation.

The line between improvising and composing was less clearly drawn in solo improvising because here the player normally had his own repertory, playing from memory, improvising and often changing his compositions and re-using materials from earlier improvisations. The fact that there were so many famous keyboard composers was no doubt due to this practice. The large number of collections of printed works for keyboard, lute and similar instruments in the 16th century, bringing music from the repertory and inventions of the professional performer into the hands of the amateur, led to a great change. The works of the professional virtuoso, whether devised through his own improvisations, worked out on his instrument in playing or first created in written notation, became in published form the repertory for the amateur, and improvisation became associated with the professional virtuoso.

Improvisation, §II: Western art music.