
Verdi himself conducted, and the four soloists were Teresa Stolz (soprano), Maria Waldmann (mezzo-soprano), Giuseppe Coppini (tenor) and Ormando Maini (bass). The Requiem was first performed the following May in the church of San Marco in Milan, on the first anniversary of Manzoni's death. It included a revised version of the "Libera me" originally composed for Rossini. Verdi travelled to Paris in June, where he commenced work on the Requiem, giving it the form we know today.

Upon hearing of his death, Verdi resolved to complete a Requiem-this time entirely of his own writing-for Manzoni. In May 1873, the Italian writer and humanist Alessandro Manzoni, whom Verdi had admired all his adult life and met in 1868, died. In the meantime, Verdi kept toying with his "Libera me," frustrated that the combined commemoration of Rossini's life would not be performed in his lifetime. The piece fell into oblivion until 1988, when Helmuth Rilling premiered the complete Messa per Rossini in Stuttgart.

Verdi never forgave Mariani, although Mariani pleaded with him. He pointed to Mariani's lack of enthusiasm for the project, even though he had been part of the organising committee from the start, and it marked the beginning of the end of their long-term friendship. Verdi blamed the scheduled conductor, Angelo Mariani, for this. However, on 4 November, nine days before the premiere, the organising committee abandoned it. The premiere was scheduled for 13 November 1869, the first anniversary of Rossini's death. When Gioachino Rossini died in 1868, Verdi suggested that a number of Italian composers should collaborate on a Requiem in Rossini's honor, and began the effort by submitting a "Libera me." During the next year a Messa per Rossini was compiled by 13 composers (of whom the only one well known today is Verdi himself).

The Requiem is scored for a quartet of solo singers ( soprano, mezzo-soprano, tenor and bass), double chorus and a large orchestra consisting of three flutes (third flute doubling on piccolo), two oboes, two clarinets, four bassoons, four horns, eight trumpets (four of which play from offstage during the Tuba mirum), three trombones, one ophicleide (an obsolete instrument usually replaced by a tuba in modern performances), timpani, bass drum, and strings.
