The eight voices are not incorporated classically but rather speak, whisper and shout excerpts from texts including Claude Lévi-Strauss' The Raw and the Cooked, Samuel Beckett's novel The Unnamable, instructions from the scores of Gustav Mahler and other writings.

Leonard Bernstein states in the text version of his Charles Eliot Norton Lectures from 1973 that Sinfonia was representative of the new direction classical music was taking after the pessimistic decade of the sixties.

[1] Originally commissioned by the New York Philharmonic for its 125th anniversary, Sinfonia was premiered on October 10, 1968 by the orchestra and The Swingle Singers, with Berio conducting.

In the months after the premiere Berio added a fifth movement, which was first played when Sinfonia was performed during the 1969 Donaueschingen Festival by the Southwest German Radio Symphony Orchestra conducted by Ernest Bour, and subsequently in London at the July 22 Promenade concert, with the BBC Symphony Orchestra and The Swingle Singers conducted by the composer.

[2] The New York Philharmonic first played the five movement version of Sinfonia on October 8, 1970, conducted by Leonard Bernstein, to whom the work is dedicated.

He had read the interview, several years after the fact, and assured me that the movement of this symphony offered the musical counterpart of the mythical transformation I was revealing.

The orchestra plays snatches of Claude Debussy's La mer, Maurice Ravel's La valse, Igor Stravinsky's The Rite of Spring, as well as quotations from Arnold Schoenberg, Anton Webern, Johannes Brahms, Henri Pousseur, Paul Hindemith, and many others (including Berio himself) creating a dense collage, occasionally to humorous effect.

[10] The text from Beckett at this point begins, "So after a period of immaculate silence there seemed", but, instead of continuing the quotation ("a feeble cry was heard by me"), Berio substitutes the words "to be a violin concerto being played in the other room in three quarters" and then, after the Berg quotation, alto 2 insists on "two violin concertos", at the point where Berg is interrupted by Brahms.

[13] Berio himself describes the movement as a "Voyage to Cythera"[14] in which a ship filled with gifts is headed towards the island dedicated to the goddess of love.

The movement revisits the text from the previous sections, organizing the material in a more orderly fashion to create what Berio calls "narrative substance".