During the first decades of the 20th century unconventional notation appeared in contemporary music in order to address a range of experimental concerns. The 1950s and 60s were something of a golden age for graphic notation, when the composers of the New York School John Cage, Morton Feldman, Earle Brown, and Christian Wolff began experimenting with indeterminacy and investigated graphic notation as a way to restrict and reinvent the information given to performers. Another important inspiration for experimental notation was the advent of electronic and tape composition. For electronic composition, a score was after the fact and thus essentially decorative. Many early electronic works by Ligeti and Stockhausen, especially, have beautiful graphic scores. Soon after, the Fluxus movement took the concept of the score into the realm of the absurd. Paik, George Brecht, Yoko Ono, and many others began creating unrealizable scores, as well as scores for actions that abandoned traditional musical instruments—and musicians—entirely. The 1960s and ’70s produced composers and artists who were in constant conversation with one another. In addition to its dialogue with other disciplines, composition and notation began to feel the influence of jazz, especially regarding improvisation. Earle Brown, who began as a jazz trumpeter and began exploring open notational approaches in the 1950s, describes his work both as influenced by the dynamic aesthetics of Jackson Pollock and Alexander Calder and as “secretly” exploring why classical musicians could not improvise. From the tentative revisions of the early 20th century to the proliferating, idiosyncratic practices of today, graphic notation has offered composers—and artists—a way to express what standard systems cannot. It has enabled them to say not just more, but also sometimes provocatively less than traditional scores. Sound art and the current flexibility of disciplines allow the visual components of music and the aural possibilities of space to manifest in beautiful, complex documents. At the same time, open scores have their own appeal for improvisers and others in search of answers to profound, evasive musical questions. Ever occupying the margins of sense and perception, graphic scores play an important role in bringing adventurous minds to music.
The UPIC was a unique computer music system, designed as a tool for sound synthesis, to be manipulated specifically in the physical and visual realm. Unlike previous synthesizers controlled by keyboard, this device’s ‘instrument’ was an electromagnetic pen. This pen was used to trace out a visual representation of the sonic result onto an architect's digital drawing board. This ‘score’ would then be saved in the computer’s memory, and could be converted into sound. As Gérard Pape suggests that this was “a technical and musical innovation which permitted the composer to draw all element of his [or her] score from the micro- to the macro structure of the composition. Composition of musical form and sound synthesis were, thus, unified by the UPIC’s approach”.
The idea of UPIC system goes back to 1953-54, when Iannis Xenakis wrote music for orchestra, using graphic notation for representing musical effects that were too complicated to be specified with traditional staff notation. The work Metastasis (written in 1953-54) makes systematic use of glissandi (continuous transition between two notes of different pitches). Xenakis drew the glissandi as straight lines in the pitch-versus-time domain. The score is written for sixty-one different instrumental parts. The great number of glissandi creates a sound space of continuous evolution comparable to the ruled surfaces and volumes that he used in architecture. Writing the glissandi in sixty-one different orchestra parts by hand was quite arduous. Xenakis had then to transcribe the graphic notation into traditional notation so that the music could be played by the orchestra. At this time, he came up with the idea of a computer system that would allow the composer to draw music. Indeed, graphic representation has the advantage of giving a simple description of complex phenomena like glissandi or arbitrary curves. Furthermore, it frees the composer from traditional notation that is not general enough for representing a great variety of sound phenomena. In addition, if such a system could play the score by itself, the obstacle of finding a conductor and performers who want to play unusual and "avant-garde" music would be avoided.