People today equate art music with composition — with music composed, learned, and performed separately. Things were different in the Middle Ages and Renaissance. In addition to composing, professionals and amateurs made music extemporaneously, using preexisting melodies or special formulas. Some of these techniques shared performing venues and artistic recognition with the hallowed songs, masses, and motets that have come down to us in written form, and they are the topic of Improvising Early Music. The small volume contains three essays that originated as part of the “International Orpheus Academy for Music and Theory,” held at the Orpheus Institute in Ghent in 2009. It is, however, more than just a volume of proceedings. Musicologists have traditionally focused their work on the written repertory. This book is the most valuable introduction to the topic of musical improvisation available now. Even a lay reader can at least get a good sense of the phenomenon of improvisation and of the scholarly approaches to it, though a full understanding of the essays requires knowledge of music and a familiarity with the repertory. The book’s subtitle — The History of Musical Improvisation from the Late Middle Ages to the Early Baroque — is potentially misleading. This is not a systematic history of musical improvisation, but rather a collection of three essays in which specialists discuss specific topics.

In the first section, Rob C. Wegman evokes the times when counterpoint was a living practice. He situates it between two distant chronological signposts — the 1330s, when it is first discussed in theoretical treatises, and 1600, when monody supplants polyphonic music as the leading compositional language. With his usual captivating style, Wegman proposes a continuous development of the practice from organum purum, or note-against-note style, to florid music, in which more notes are sung against one. Yet, Wegman observes, the presence of these flores does not eliminate the integrity of the contrapuntal rules even when changing styles alter the rhythmic surface of the music. In his narrative, the famous bull Docta Sanctorum Patrum by Pope John XXII stands behind the success of counterpoint. Afraid of the harsh punishments threatened by the pope, singers and composers would have adopted the framework (if not the simple sound) of note-against-note counterpoint.

In the second essay, Johannes Menke posits a substantial continuity in composition and improvisation between the sixteenth and the seventeenth century. Following Rolf Dammann, he distinguishes between con centro improvisation and composition — in which the tenor part works as the center of the activity — and an ex centro approach, characterized by a structural relationship connecting the outer voices. Through the concept of ex centro sound progressions, he links a number of phenomena, including ars combinatoria, sequences, the use of certain chords, ostinatos, and dissonances. In Menke’s analysis, ex centro reveals how the core of composition (or improvisation) moves to the surface of music, which becomes akin to the stage of a genuinely Baroque musical theater. In the final essay, Peter Schubert offers a taxonomy of Renaissance improvisation, listing techniques that allowed musicians to expand a musical texture or improvise new music. Schubert focuses on three of them: contrapunto fugato and invertible counterpoint, the addition of canonic parts, and the so-called stretto fuga, a free canonic improvisation. Schubert explains each technique, presents theoretical evidence, and illustrates it through musical pieces, before detailing the features that separate improvised music from composition.

The practical approach of these essays allows little room to discuss the limits of the present knowledge, producing a clear and deceivingly complete picture of improvisation in early music. In a different kind of publication one could wish for more information, for instance, on how the sources of cantus planus binatim used by Wegman respond to the general European-wide process he describes, rather than to local and short-term reform movements affecting Italian religious orders. There could also be a clearer acknowledgment of the chronological and geographical distance between Schubert’s theoretical sources and some of the repertory he analyzes. But perhaps one would be asking too much from a book that already accomplishes so many things. Hopefully this collection will help accelerate the next phases of research on musical improvisation, revealing more clearly the local differences and chronological turning points that even the generic descriptions of contemporaneous listeners seem to point at.