Rampazzi studied the piano at the Milan Conservatory and for a number of years studied composition at the Darmstadt summer courses. She taught electronic music at the Padua Conservatory (1972–9). After a busy career as a pianist specializing in new music, in 1958 she met John Cage and abandoned the piano to devote herself to working in, developing and disseminating electronic music.
In 1965 she founded in Padua the Gruppo NPS (Nuove Proposte Sonore) which soon became one of the leading private electronic music studios in Italy; it stood out for its interdisciplinary approach and also its spirit of collective experimentation.
Her first works were thus written in collaboration and their aim was to investigate systematically individualized sound parameters. After the Gruppo NPS ceased its activities in 1972, her work became more personal and, with the use of frequency modulation, she manipulated on tape fragments of Bach, Mozart, Stravinsky, Webern and, eventually, the human voice. The year 1975 marked the beginning of a new compositional phase, in which her vast experience of analogue electronic music was expanded by the new possibilities offered by the computer and, especially, its microscopic control of timbral parameter.