In an attempt to convince Rai managers to approve the Studio project, Berio and Maderna decided to create a powerful example of the expressive potential of new electroacoustic resources: a radio documentary dedicated to Milan and entitled Ritratto di città [Portrait of a city] (with the subtitle “Studio per una rappresentazione radiofonica” [study for a radio play]). This work (begun and completed in Dec. 1954) is considered to be Opus 1 of the Studio and anticipates, in terms of poetics and aesthetics, subsequent electroacoustic works by Berio and Maderna. The work stemmed from a collaboration with Roberto Leydi (author of the lyrics), and made use of very limited resources (including an oscillator which, according to some reports, was brought to Milan from Rai Turin, where it was used as a measuring device).
From the very beginning the Studio was equipped with four tape recorders, thus magnetic tape was the main instrument in several works (to record basic acoustic or electronic sound materials, transform them, organize sounds in time sequences through cutting and joining of tape segments, and finally edit using one or more recorders and the mixer). Examples of related works include “Thema (Omaggio a Joyce)” (1958) by Luciano Berio, for one voice, and “Serenata III” (1961) by Bruno Maderna, for flute and marimba, as well as many later works by Luigi Nono. In John Cage’s “Fontana Mix” (1958), composed during his stay at the Studio, the starting material on tape is the sounds of the streets of Milan, department stores, trams, churchs, zoo. The tape was then used to create random sequences of sound fragments of various lengths, processed and then reassembled. Yet another approach can be noted In Maderna’s “Continuo” (1958): in this cas the tape acts as a deposit for the various transformation processes of the same initial sound material.
The most stimulating challenge for composers at the Studio was the use of purely electronic sounds. Using the nine available sinusoidal oscillators, mixtures of relatively complex sounds could be created and provided the basis for an additive sound synthesis. Lietti had also constructed a cathode-ray tube control which allowed to visually “tune” the oscillators frequencies to harmonic ratios. This equipment can be heard in Berio’s “Mutazioni” (1956), a composition for sinusoidal sounds based on the permutation of duration, frequency and entry. In another early electronic work, “Notturno” (1956) Maderna used instead a subtractive synthesis approach in which sounds were created by filtering white noise with a “selective amplifier”, basically a resonant filter that could reach a bandwidth as thin as 4 Hz: white noise passed through this filter converged towards a sinusoidal sound.
The 1960’s saw a progressive trend towards the production of theatre music, with works by Maderna, Giacomo Manzoni and Luigi Nono: the latter was to become the main composer of the Studio during these years. Nono developed a technique based on the organisation of basic materials that were already musical, such as the choruses of “Music for Die Ermittlung” by Peter Weiss (1965), used in “Ricorda cosa ti hanno fatto in Auschwitz” (1966). Alternatively, he used materials with particularly significant semantic value, such as sounds of industrial blast furnaces and laminators heard in “La fabbrica illuminata” (1964). According to Nono’s own words, he always started with the sound material and “listen-analyse-listen, continuous listening: The musical thoughts would slowly and suddenly become clear.” Nono gradually developed specific working practices with the magnetic tape, paying specific attention to the projection of sound in space. In “La fabbrica illuminata”, the space was already defined on quadraphonic concert tape. In “Ricorda cosa ti hanno fatto in Auschwitz”, on the other hand, the quadraphonic tape contains a single monophonic signal that Nono would spatialize live during performances, interacting directly with the physical place of the venue. These and other works in fact show how Nono used space as a compositional parameter.