Born in the village of Pitelli near La Spezia, Scelsi spent most of his time in his mother's old castle where he received education from a private tutor who taught him Latin, chess and fencing. Later, his family moved to Rome and his musical talents were encouraged by private lessons with Giacinto Sallustio. In Vienna, as a disciple of Arnold Schönberg, he became the first adept of dodecaphony in Italy, although he did not continue to use this composition system. In the 1920s, Scelsi made friends with intellectuals like Jean Cocteau and Virginia Woolf, and travelled abroad extensively. In 1927, in Egypt, he first came into contact with non-European music. His first composition was Chemin du coeur (1929). Then followed Rotativa, first conducted by Pierre Monteux at Salle Pleyel, Paris, on 20 December 1931.
In 1937, he organised a series of concerts of contemporary music, introducing the music of (among others) Hindemith, Schoenberg, Stravinsky, Shostakovitch, and Prokofiev to an Italian audience for the first time. Due to the enforcement of racial laws under the fascist regime of Benito Mussolini, these concerts were not able to continue for long, preventing the performance of works by Jewish composers. Scelsi refused to comply, causing the composer's gradual removal from Italy. In 1940, when Italy entered the war, Scelsi was in Switzerland, where he remained until the end of the conflict, composing and improving his conception of music. He married Dorothy Kate Ramsden, a divorced Englishwoman.
Back in Rome after the war, his wife left him (eventually inspiring Elegia per Ty), and he underwent a profound psychic crisis that eventually led him to the discovery of Eastern spirituality and also to a radical transformation of his view of music, his so called second period. He rejected the notions of composition and authorship in favour of sheer improvisation. These improvisations, recorded on tape, were later transcribed by collaborators under his guidance, then orchestrated and complemented by the composer's meticulous performance instructions, or adjusted from time to time in close collaboration with the performers.
Scelsi came to conceive of artistic creation as a means of communicating a higher, transcendent reality to the listener. From this point of view, the artist is considered a mere intermediary. It is for this reason that Scelsi never allowed his image to be shown in connection with his music; he preferred instead to identify himself by a line under a circle, a symbol of Eastern provenance. Some photographs of Scelsi have emerged since his death.
One of the earliest interpreters Scelsi closely worked with is the singer Michiko Hirayama, whom he met in 1957 in Rome. From 1962 to 1972 he wrote the extensive song cycle "Canti del Capricorno" directly for her due to her special and unique vocal range. The writing process of the piece was an example for Scelsi's very personal way of working: developing pieces through improvisation, recording and then final transcription.
From the late 1970s, he met several leading interpreters who have promoted his music all over the world and gradually opened the gates to wider audiences, such as the Arditti String Quartet, the cellist Frances-Marie Uitti, the pianists Yvar Mikhashoff and Marianne Schroeder.
Scelsi was a friend and a mentor to Alvin Curran and other expatriate American composers such as Frederic Rzewski who lived in Rome during the 1960s (Curran, 2003, in NewMusicBox). Scelsi also collaborated with other American composers including John Cage, Morton Feldman, and Earle Brown who visited him in Rome.
Alvin Curran recalled that: "Scelsi ... came to all my concerts in Rome even right up to the very last one I gave just a few days before he died. This was in the summer time, and he was such a nut about being outdoors. He was there in a fur coat and a fur hat. It was an outdoor concert. He waved from a distance, beautiful sparking eyes and smile that he always had, and that's the last time I saw him" (Ross, 2005).
Scelsi died in Rome on 9 August 1988.