Spiral (Stockhausen)

Spiral (Spiral [adj.], Spirally), for a soloist with a shortwave receiver, is a composition by Karlheinz Stockhausen, written in 1968. It is Number 27 in the catalogue of the composer's works.
Conception.
"Spiral" is one of a series of works dating from the 1960s which Stockhausen designated as "process" compositions. These works in effect separate the "form" from the "content" by presenting the performers with a series of transformation signs which are to be applied to material that may vary considerably from one performance to the next. In "Spiral" and three companion works ("Kurzwellen" for six performers, "Pole" for two, and "Expo" for three), this material is to be drawn spontaneously during the performance from short-wave radio broadcasts. The processes, indicated primarily by plus, minus, and equal signs, constitute the composition and, despite the unpredictability of the materials, these processes can be heard from one performance to another as being "the same".
History.
"Spiral" was composed in Madison, Connecticut in September 1968 and was premiered on 15 May 1969 at the Muzički Biennale Zagreb, with the oboist Heinz Holliger as the soloist. Holliger performed it subsequently in Saint-Paul de Vence, and on 10 July 1969 at the Cheltenham Music Festival. Between 14 March and 14 September 1970, "Spiral" was given 1300 times at Expo '70 in Osaka, Japan, in daily performances by twenty different musicians including the composer. The score is dedicated to the other nineteen: the six singers of the Collegium Vocale Köln (Dagmar Apel, Gaby Rodens, Helga Albrecht, Wolfgang Fromme, Siegfried Bernhöft, and Hans Alderich Billig), and instrumentalists David C. Johnson (flute with synthesizer), Michael Vetter (electric recorder), Edward Tarr (trumpet), Karlheinz Böttner (electric guitar), Christoph Caskel and Michael Ranta (percussion), Rolf Gehlhaar (tamtam), (electronium and piano), Peter Eötvös (55-chord and piano), Gérard Frémy and Aloys Kontarsky (piano), Johannes Fritsch (electric viola), and Mesías Maiguashca (sound direction).
Structure and technique.
"Spiral" consists of a sequence of 206 events, grouped into ten sections which are divided in the score by wavy barlines. Stockhausen explained that in pieces like this, "the first step is always that of imitating something and the next step is that of transforming what you're able to imitate". The first event is realized with the short-wave receiver and the instrument/voice together. The subsequent events freely alternate performance by the radio, by the instrument or voice, and their combination, though a balance should be aimed for between events with and without radio sounds.
Each plus, minus, or equal sign indicates that, upon repetition of an event, the performer is to increase, decrease, or maintain the same level in one of four musical dimensions (or "parameters"): overall duration of the event, number of internal subdivisions, dynamic level, or pitch register/range. It is up to the performer to decide which of these dimensions is to be affected, except that vertically stacked signs must be applied to different parameters. Despite this indeterminacy, a large number of plus signs (for example) will result in successive events becoming longer, more finely subdivided, louder, and either higher or wider in range; a large number of minus signs will produce the reverse effect. To the signs previously used in "Prozession" and "Kurzwellen", Stockhausen adds a dozen new ones. An especially important one is the "spiral sign", consisting of a column of different combinations of four or five plus or minus signs bracketed by repeat marks. At this sign, the performer is to repeat the previous event several times, transposing it each time in all parameters, and attempt to transcend not only previous limits reached in the piece, but also to go beyond the limitations of the instrument/voice itself. In doing this, the performer is encouraged to employ visual and theatrical possibilities. Because there are only seven "spiral" signs altogether, not every section contains one of them. "Spiral" is not ordinarily performed complete: the performer may end a version at any of the wavy barlines, and then for the next performance should resume where the previous one left off. On the other hand, the end of the score is marked "da capo" so that, should a chosen starting point result in the end being reached too soon, the performer may continue again from the beginning. Most performances last between fifteen and twenty-five minutes, and Stockhausen did not authorise a full-length version until Michael Vetter convinced him to permit such a thing. The first complete performance was realised by Michael Vetter and was recorded on 22 November 1995 at the Ballhorn Tonstudio in Odenthal.