After the Second World War and a period of controlling more and more aspects of performance, many composers rediscovered an old phenomenon: improvisation. At first glance, the word “improvisation,” which has been used since the 14th century, seems to refer to a clear-cut concept—”to compose or simultaneously compose and perform on the spur of the moment without any preparation.” It literally means to do something unforeseeable. Yet improvisation appears as a complex notion since it has been used within innumerable contexts such as Gregorian Chant, Jazz, and even Non-Western music. The notion of improvisation is further blurred as it points toward such 20th-century concepts as indeterminacy, aleatory, open form, experimental, and meditative music.
But what defines musical improvisation today and how does it relate to composition? While trying to nail down criteria like spontaneity, naturality, absence of notation, and singularity of results, which could determine the nature of improvisation, one discovers that they can apply to composition as well. Improvisation is an ambiguous concept; it can be realized in a free manner. It can be based on strict orally passed on rules, patterns, and formulas. It can depend on written sketches and arrangements (Jazz) or be a constituent of a mostly written-out composition. Improvisation can refer to the act of spontaneous invention (similar to composition, that is why some prefer to speak of “oral” or “instant” composition). It can refer to the act of immediate performance (not interpretation), to a flexible dimension within a composition as well as to a finished, recorded, or notated product. Sometimes improvisation is regarded as equivalent or even superior to composition. Even Schoenberg, in his essay “Brahms the Progressive,” regarded composition as a “slowed-down improvisation.” And Ferruccio Busoni, in his 1907 Entwurf einer neuen Ästhetik der Tonkunst, considered composition as a mere expedient to preserve improvisation. The techniques are similar, but whereas the composer can use pencil and eraser, the improviser has the even more demanding task of succeeding extempore. Yet, quite often improvisation is looked upon as inferior to composition. Improvisation can connote unpreparedness, simplicity, rawness, orality, transitoriness, and aimless play. Further it appears as a rather dubious practice when misleadingly described in some dictionaries as “music put together without forethought” (from the article on “Composition” in the 1980 edition of The New Grove Dictionary of Music and Musicians) or “without the aid of manuscript, sketches or memory” (from “Improvisation” in the 1960 edition of The Harvard Dictionary of Music).
When improvisation came into focus in the 1950s, it seemed to threaten the conventional musical work, its structure, form, notation, and permanence. Happenings, collective compositions and improvisations, chance music, “graph” and text compositions, and various elements of indeterminacy seemed to “decompose” the established and firm work of art. Composers searched for new ways of notating uncommon sounds and actions and allowed the performers a great deal of flexibility. The process character of music, its transitory nature, and its significance as a “time” art was emphasized, whereas “opus music” due to its object character became suspicious, conservative.
Due to misconceptions in regard to improvisation and due to varying new artistic approaches, many composers came up with new terms such as indeterminacy, aleatory, open form, experimental, and meditative music and provided their own new definition of improvisation. Yet, this led to a considerable confusion of concepts. Critics and musicologists in particular juggled with the new words and used them interchangeably so that it has remained unclear what the differences are.
The manifold new concepts of improvisation that were developed in the middle of the last century indeed puzzled a great many performers and listeners as well and stirred up the conservative music world. They involved many performance practice problems and certainly will continue to in the following centuries if these works outlast our own time. But nevertheless new experiences were made and the musical repertoire was enriched. Further new light was shed on old categories such as composition, performance, interpretation, and improvisation. Since the sixties and seventies new generations of improvising performers able to deal with improvisatory concepts have come into focus. Improvisation has gained considerable importance in music education and music therapy. Many composers and improvisers have created a greater awareness of the wealth of Non-Western music. After all, audiences have become generally more open-minded and more courageous in dealing with the musical “imprévu”—the unforeseen.