"Spatial music" (or its partial synonim "instrumental theatre") is a term refering to the experiments with musical sounds moving in space. Initially these experimens in their modern form had attracted attention at the beginning of XX century. Their origin is usually connected with "aesthetic futurology" of composer A.N.Scriabin.
Already in "Prometheus" the composer suggested to introuce the elements of theatre into musical performance. Later on he meditated: "Maybe the orchestra itself will take part in a movements and processions... It should live in movement, as well as a chorus should. It's nearly a dance". At the same time Scriabin dreamed of some soundings "from the heaven", i.e. of the forms of sound localization and moving, which was impossible at that time.
Such aspect of music is studied now by a number of researchers. As it appears, already the orchestra in Ancient Greece demonstrated multi-chorus performances (with a separate groups of actors). In most obvious way this method was displayed in baroque orchestra, which inherited it from antiphonal polyphony of XVI century and from responsory principle of composition and performance, assumed in liturgy service (J.Gabrieli, G.Schutz, S.Scheidt, O.Banevoli and later on Bach and Handel). The methods of spatial separations of performers, conditioned with the logic of stage action, were used in musical theatre ("Don Giovanni" by Mozart, then "Prince Igor" by Borodin). The localization of instruments in symphonic music later on was used more rarely ("Music in he Forest" by Handel, "Serenade" by Mozart, "Requiem" by Berlioz). In the orchestra of XIX century, unlike baroque epoch, the principle of single chorus began to dominate (on our opinion, this corresponded to the transition from polyphonic writing to homophonic one, in the course of music development).
At the beginning of XX century the interest to "spatial music" arosed again - together with the assimilation of new polyphony and evolution of symphony genre, first of all in the works by G.Mahler and C.Ives. Later on the experiments in this field were carried out by E.Satie (being the organic part of his "sound wallpaper" project); A.Schoenberg (oratorio "The Ladder of Jacob"); E.Varese (the piece "Integrals" for percussion instruments). The new methods of theatralization and "spatial music" were demanded by the music itself, for it has achieved the highest level of expression and entered, in consequence, into the area of some "external gesture" (inluding, by the way, its transition into visual effects). These were also an organic feature of "point", sonorous music, that use "frozen" structures, where individual sounds play a role of self-depended "characters". A.Dymshitz from Leningrad had conducted interesting experiments in 1927, trying to build the so-called "spatial metallophon", it's sounding elements being arranged all over the concert hall and were controled remotely. Also S.Eisenstein had forced sound to travel in his performance of "Wolkiries" (1940).
Of course it was more suitable, from technical point of view, to realize all that by means of electroacoustic tools, combined with a living orchestra as it was done in the performances by S.Eisenstein, A.Schoenberg, K.Stockhausen, P.Boulez, E.Varese. But the experiments on theatralization of the ingenious musical composition never stopped, and this art school had been named as "instrumental theatre". Xenakis, in his "Terretecktor", had arranged the orchestra members just among the spectators. Among other foreign experiments it should be mentioned the works by A.Dobrovolsky (Poland), L.Verle (Sweden), M.Kagel (Argentina). Among the Russian musicians one may distinguish A.Schnitke (opera "The Eleventh Commandment"). As for instrumental and symphonical plays, the effect of "moving instruments" were used in "Antiphones" by S.Slonimsky, "Small Play" by B.Kutavichus. The greatest resounance was caused, in its time, by the Second Symphony by A. Schnitke (1972).
But, of course, more organic and natural way is the use of moving sound effect in the process of electronic music perception, in its actual form of existence - the reproduction by electroacoustic facilities. Strictly speaking, the usual concert music always contains elements of theatralization, giving the food for eye. The listener used to see what physical (visually perŠeived) process is responsible for that sound or another. And even listening usual music by the record, one can imagine and "see" the process of sound's birth (owing to the former synesthetic experience). Therefore in this case the loud-speaker is not the primary source of sound, but a mere reproductor.
The perception of electronic music is quite different. It's timbres differ from the habitual ones, they are created regardless the performer's gesture, arising from the deeps of "black box". Here the loud-speaker appears as primary source of sounds, and the listeners always noted the unnatural character of looking at the empty stage. That is the true reason of eletronic music's natural attitude to the synthesis with visual elements, which take the role of sounds' source (cinema and slide projection, pantomime, light-music). Just the electronic music has declared, most clearly, the necessity of such aspect of performance as the movement of sound, allowing one to create illusion of a certain spatial action (though invisible), that results in the emergence of electronic sound. Just in this case, when new dynamic parameter - sound's position - is added to the habitual ones (intensity, pitch, timbre, duration) - the most optimal embodiment of "spatial music" becomes possible. Its high potentials have been confirmed in the course of the following art events: the performance of "Electronic Poem" by E.Varese in "Phillips" Pavillion at EXPO-58 (Brussels); "Polytop" by J.Xenakis in Parisian Thermae and in France Pavillion at EXPO-67 (Montreal); "The Garden of Sounds" by K.Stockhausen in the underground grotto in Beirut and in Germany Pavillion at EXPO-70 (Osaka); the "spatial music" concerts, conducted by "Prometheus" design office at the State Exhibition of USSR in 1974. In the most events music was combined with visual effects and a specific concert halls of closed shape were used. By the way, Scriabin dreamed of exactly such concert halls to play light-music in. The light-music studio in Kazan is equipped for "spatial music" performances too.
Finally, in ideal case, the "spatial music" performer should be able to move freely the sound's sources of certain instruments at any trajectory, either in the plane or in the space of concert hall, according to the music theory rules. The spatial trajectory would "repeat" and emphasize the melody line, thus revealing, first of all, thematic development, closely connected with the instrumentation. (This method could be applied to play usual music also, provided its parts (instruments, themes) have been recorded separately). Of course, the perception and distinction of these trajectories would not be so clear-cut as visual ones. But in case the sound's space is used to a full extent, a certain effect can be achieved. It is also possible to apply the "spatial music" methods to light-music composition, keeping some specific rules. For instance, the sound might move either together with a corresponing visual element, or in opposite way. In the first case the illusion of "sounding object" movement is created (this may be called, conventionally, as unison movement of sound and light). While the second case may be called, conventionally, as polyphonic movement of sound and light.