Pier Leone Ghezzi, caricature of Francesco Gasparini. Biblioteca Apostolica Vaticana, Codici Ottoboniani latini 3113. Via Wikimedia Commons (public domain).
In 1708 a book of just over a hundred pages appeared in Venice under the title L’armonico pratico al cimbalo. Its author was Francesco Gasparini, choirmaster of the Ospedale della Pietà, which is to say Vivaldi’s boss. The book explains something that is hardly taught any more: how to accompany at the harpsichord starting from a line of bass with numbers above it, inventing everything else as you play.
Let us stop for a moment on what that means. Throughout European music between 1600 and 1750, the part for harpsichord, organ, lute or harp was not written out. The composer supplied the bass and figures that indicated the chords. What to actually play, how many voices, in which register, with what ornaments, was decided by the performer in real time. Every performance was different. The text was deliberately incomplete, and it is one of the most radical differences between that music and ours.
Gasparini writes for someone who has to learn to do it, so the book is concrete to the point of pedantry. It begins with the elementary things, how chords are laid out on the figures, then moves on to situations where the sign is not enough and you have to understand where the music is going. There is a chapter on the acciaccature, notes added inside the chord that do not belong to it, played together with the others and released at once, to give bite. There is the way to accompany recitative, which is the most delicate part because the accompanist must stay behind a singer who is speaking, not singing in time.
The treatise was reprinted throughout the eighteenth century, which says two things: that it was truly needed, and that it was needed for a long time. Its buyer was no theorist but a young man who would have to sit down the following week to accompany an opera or a Mass and get through it.
The practice ends with classicism. When the orchestra becomes self-sufficient and the composer writes out all the parts, the basso continuo disappears, and with it the figure of the musician who composes while performing. It is a loss that changed the nature of the profession: from that moment the performer becomes someone who realises another person’s intentions, and creation moves entirely to the composer’s desk.
The paradox is that the skill survived elsewhere. A jazz pianist who reads a chord symbol and builds the accompaniment does exactly what Gasparini taught, with a different harmonic vocabulary and the very same mental operation: from a symbol, in real time, drawing out a texture. Those who studied the two things separately often fail to notice, because in Italian conservatories they sit in different departments and do not talk to each other.
Anyone who wants to see the book can. It is in the public domain, digital reproductions of the eighteenth-century copies exist, and it reads better than one fears: Gasparini’s Italian is dry, the examples are short, and anyone with a minimum of keyboard skill can try them while reading. What strikes you most, after a few pages, is the tone. He does not lay out rules to be obeyed. He explains how a thing is done, as a craftsman would who puts his hands over your hands.
In the Melos library the volume sits beside the Neapolitan partimenti, and the pair says everything about the method of the time: two books that contain no music to perform, but instructions for making it.