In contrast to more traditional musical textures, perceptually, and as a compositional technique / analytic tool, the concept of a sound mass (also called sound collective, sound complex, tone shower, sound crowd, or cloud) composition "minimizes the importance of individual pitches in preference for texture, timbre, and dynamics as primary shapers of gesture and impact." Explored by Charles Ives and Henry Cowell in the early part of the twentieth century, this technique also developed from the modernist tone clusters and spread to orchestral writing by the mid 1950s and 1960s. J. Michele Edwards (2001, pp. 326–27) considers that a sound-mass "obscures the boundary between sound and noise". In auditory scene analysis, ASA, a more precise description would place "sound mass" closer to "integration" on the continuum between integration and segregation. ASA makes it clear that the definition of the limits of "sound mass" is psychoacoustic in nature.
Techniques which may create or be used with sound mass include extended techniques such as muted brass or strings, flutter tonguing, wide vibrato, extreme ranges, and glissandos. The continuum for "sound mass" moves from simultaneously sounding notes – clusters etc., towards stochastic cloud textures, and 'mass structure' compositional textures which evolve over time (ibid[verification needed]). Examples of this continuum can be found in Metastasis (1953–54), Pithoprakta (1955–56), and Achorripsis (1956–57), all orchestral works by Iannis Xenakis (Salzman 1987, 185), as well as in Gesang der Jünglinge for concrete and electronic sounds (1955–56), Zeitmaße for five woodwinds (1955–56), and Gruppen for three orchestras (1955–57), by Karlheinz Stockhausen (Stockhausen 1963, 235). Other composers and works include Barbara Kolb, Pauline Oliveros' Sound Patterns for chorus (1961), Norma Beecroft's From Dreams of Brass for chorus (1963–1964), and Nancy Van de Vate. Beecroft "blurs individual pitches in favor of a collective timbre through the use of vocal and instrumental clusters, choral speech, narrator, and a wash of sounds from an electronic tape" (ibid[verification needed]).
A very early example is the opening of Jean-Féry Rebel's ballet Les Elémens (1737–38), where chaos is represented by a gradually cumulating orchestral cluster of all seven notes of the D minor scale (Henck 2004, pp. 52–54). A later example is the third movement of Ruth Crawford Seeger's String Quartet 1931 (Nonesuch H-71280) while more recently Phill Niblock's multiple drone based music serves as an example. The use of "chords approaching timbres" begins with Debussy and Edgard Varèse often carefully scored individual instrumental parts so that they would fuse into one ensemble timbre or sound mass (Erickson 1975, pp. 18 and 21).
Other examples include European "textural" compositions of the fifties and sixties such as Krzysztof Penderecki's Threnody to the Victims of Hiroshima (1959) and György Ligeti's works featuring micropolyphony in works like Atmosphères (1961) and his Requiem (1963-65). Other composers with works using this technique include Henryk Górecki, Karel Husa, Witold Lutosławski, Kazimierz Serocki, and Steven Stucky. Sound mass techniques also appear in the music of George Crumb (Anon. n.d.).
- Anon. n.d. "Synopsis of Twentieth Century Styles and Composers". University of Northern Colorado website (Archive from 2 September 2005, accessed 20 October 2011).
- Composers Quartet (1973). Nonesuch H-71280.[full citation needed]
- Edwards, J. Michele (2001). "North America since 1920". In Women & Music: A History, second edition, edited by Karin Pendle. Bloomington: Indiana University Press. ISBN 0-253-21422-X.
- Erickson, Robert (1975). Sound Structure in Music. University of California Press. ISBN 0-520-02376-5.
- Henck, Herbert (2004). Klaviercluster: Geschichte, Theorie und Praxis einer Klanggestalt. Signale aus Köln 9. Münster: LIT Verlag. ISBN 3-8258-7560-1.
- Kokoras, Panayiotis (2005). Towards a Holophonic Musical Texture. In proceedings of the ICMC2005 – International Computer Music Conference. Barcelona, Spain.
- Salzman, Eric (1987). Twentieth-Century Music: An Introduction, third edition. Prentice-Hall History of Music Series. Englewood Cliffs, N.J: Prentice-Hall. ISBN 0-13-935057-8.
- Stockhausen, Karlheinz (1963). "Erfindung und Entdeckung". In his Texte zur Musik 1, edited by Dieter Schnebel, 222–58. DuMont Dokumente. Cologne: Verlag M. DuMont Schauberg.
- Xenakis, Iannis (1992). Formalized Music: Thought and Mathematics in Composition, second, expanded edition (Harmonologia Series No.6). Stuyvesant, NY: Pendragon Press. ISBN 1-57647-079-2. Reprinted, Hillsdale, NY: Pendragon Press, 2001.