musical phrases extracted from existing music, either live or pre-recorded. In order to achieve credible improvisation in particular style, machine improvisation uses machine learning and pattern matching algorithms to analyze existing musical examples. The resulting patterns are then used to create new variations "in the style" of the original music, developing a notion of stylistic reinjection. This is different from other improvisation methods with computers that use algorithmic composition to generate new music without performing analysis of existing music examples. See also Bar-line shift Free improvisation Improvisation in music therapy Impro-Visor (software) Jam session List of free improvising musicians and groups Music for People Musical collective Musics (magazine) Non-lexical vocables in music Prepared guitar Prepared piano Side-slipping S.P.I.T Notes Sources English translation by Warren E. Hultberg and Almonte C. Howell Jr, as The Art of Playing the Fantasia (Pittsburgh, Pennsylvania.: Latin American Literary Review Press, 1991) Further reading Alperson, Philip. 1984. "On Musical Improvisation". The Journal of Aesthetics and Art Criticism 43, no. 1 (Fall): 17–29. Bailey, Derek. 1992. Improvisation: Its Nature and Practice in Music, revised edition. London: British Library National Sound Archive. . Berliner, Paul. 1994. Thinking in Jazz: The Infinite Art of Improvisation. Chicago: University of Chicago Press. (cloth); (pbk). Crutchfield, Will. 2001. "Improvisation: II. Western Art Music: 5. The Nineteenth Century: (ii) Vocal music". The New Grove Dictionary of Music and Musicians, second edition, edited by Stanley Sadie and John Tyrrell. London: Macmillan. Czerny, Carl. 1833. L'art de préluder: mis en pratique pour le piano par 120 examples de préludes, modulations, cadenses et fantaisien de tous genres. Paris: M. Schlesinger. Ferand, Ernest T. 1938. Die Improvisation in der Musik; eine Entwicklungsgeschichtliche und Psychologische Untersuchung. Zürich: Rhein-Verlag. Friedrich, Otto. 1989. Glenn Gould: A Life and Variations. New York: Random House. . Guido d'Arezzo. 1978. "Micrologus" [ca. 1027], translated by Warren Babb. In Hucbald, Guido, and John on Music: Three Medieval Treatises, edited, with introductions, by Claude V. Palisca; index of chants by Alejandro Enrique Planchart, 57–83. Music Theory Translation Series 3. New Haven and London: Yale University Press. . Hall, Lucy. 2002. " They're Just Making It Up—Whatever Happened to Improvisation in Classical Music?" The Guardian (12 June). Heartz, Daniel. 1958–63. "The Basse Dance, Its Evolution Circa 1450 to 1550". Annales musicologiques 6:287–340. Kertz-Welzel, Alexandra. 2004. "Piano Improvisation Develops Musicianship". Orff-Echo 37, no. 1:11–14. Koenig, Wolf, and Roman Kroitor (prod./dir.). 1959a. Glenn Gould: Off the Record. Film,