4 | The Rise of Instrumental Music

• Dance, the first of these sources (and one we have already discussed), reaches all the way back to the Middle Ages (see page 74). In the Baroque period dance received a special impetus from opera, the genre that most fascinated people at the time. Opera was firmly linked to ballet, with frequent and sometimes elaborate dance episodes. We have seen a modest example of this in the final chorus of Dido and Aeneas. Musicians, especially in France, the center of ballet at the time, would put together sets of dances selected from operas or ballets. These dance suites, as they were called — groups of dances — could then be played by an orchestra and enjoyed apart from an actual stage performance.

  Composers also wrote many dances and suites for harpsichord. These are stylized dances, pieces written in the style or the form of dance music but intended for listening rather than dancing, for mental rather than physical pleasure.

• Virtuosity was the second source from which composers of instrumental music drew. As long as instruments have existed there have surely been virtuoso players ready to show them off — and audiences ready to applaud the show. But the art of early virtuosos was improvised and scarcely ever written down; only in the sixteenth and seventeenth centuries was some of their art incorporated systematically into written-out compositions. Even then, not all the virtuosity on which the compositions depended for their effect was notated. Much was left to be improvised, and so modern performers often have to learn how to play a good deal more than what appears in the old scores.
• Vocal music was the third source for instrumental music. More specifically, the principal technique of vocal music, imitative polyphony (imitation), was transferred to the instrumental medium. In fact, this had happened already toward the end of the Renaissance, when several instrumental genres were modeled on vocal music in this way. Each genre consists of a series of points of imitation (see pages 64 and 66) built on different motives, like a motet or a madrigal.

  From these genres emerged the characteristic polyphonic genre of the Baroque era, the fugue (fewg). A typical fugue uses only one theme throughout — like a single extended point of imitation — and often treats that theme with great contrapuntal ingenuity and learning. The art of improvising and writing fugues was practiced especially by keyboard players: organists and harpsichordists. We will discuss fugue more fully in Chapter 10.

  Vocal music influenced instrumental music in another way as well. It gaveinstrumentalists a fund of materials they could use as the basis for sets of variations — that is, sectional pieces in which each section repeats certain musical elements while others change around them.