Verdi's Requiem

The Messa da Requiem is a musical setting of the Roman Catholic funeral mass (Requiem) for four soloists, double choir and orchestra by Giuseppe Verdi. It was composed in memory of Alessandro Manzoni, an Italian poet and novelist whom Verdi admired. The first performance, at the San Marco church in Milan on 22 May 1874, marked the first anniversary of Manzoni's death. The work was at one time called the Manzoni Requiem. It is rarely performed in liturgy, but rather in concert form of around 85–90 minutes in length. Musicologist David Rosen calls it 'probably the most frequently performed major choral work composed since the compilation of Mozart's Requiem.'

After Gioachino Rossini's death in 1868, Verdi suggested that a number of Italian composers collaborate on a Requiem in Rossini's honor. He began the effort by submitting the concluding movement, the Libera me. During the next year a Messa per Rossini was compiled by Verdi and twelve other famous Italian composers of the time. The premiere was scheduled for 13 November 1869, the first anniversary of Rossini's death.

However, on 4 November, nine days before the premiere, the organising committee abandoned it. Verdi blamed this on the scheduled conductor, Angelo Mariani. 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 friendship. The composition remained unperformed until 1988, when Helmuth Rilling premiered the complete Messa per Rossini in Stuttgart, Germany.

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.

On 22 May 1873, the Italian writer and humanist Alessandro Manzoni, whom Verdi had admired all his adult life and met in 1868, died. Upon hearing of his death, Verdi resolved to complete a Requiem—this time entirely of his own writing—for Manzoni. Verdi traveled to Paris in June, where he commenced work on the Requiem, giving it the form we know today. It included a revised version of the Libera me originally composed for Rossini.

...
Wikipedia