After this, Berlioz claimed to have destroyed the entire score, except for the Resurrexit, but in 1991 a Belgian schoolteacher, Frans Moors, came across a copy of the work in an organ gallery in Antwerp, and it has since been revived.

Scored for soprano, tenor, (prominent) bass, mixed chorus, and large orchestra, including Piccolo (opt.

), 2 flutes, 2 oboes, 2 clarinets (C) 2 bassoons, 4 horns, 4 trumpets, 3 trombones (ATB), serpent, buccin (or ophicleide), timpani, cymbals Tamtam, Harps (opt.

Berlioz approached Valentino, who examined the score and agreed to conduct the performance, despite grave doubts concerning the forces at his disposal.

[1] Berlioz described it in his memoirs:[2] On the day of the full rehearsal our 'huge forces' assembled and proved to consist of a chorus of twenty (fifteen tenors and five basses), a dozen choirboys, nine violins, a viola, an oboe, a horn and a bassoon.

I suffered the torments of the damned; and my long-cherished vision of a full orchestral performance had, for the moment, to be abandoned.Berlioz had heard enough to make important revisions to the score, after which he copied out all the new parts himself.

In late January 1825 he tried without success to arrange a performance at the Church of Sainte-Geneviève (today the Panthéon), with Henri-Étienne Dérivis, a bass at the Paris Opera, to sing the solos.

[4] The curé of Saint-Roch had selected 10 July, the feast of the Sacred Heart, for a performance of the Mass, and some musicians and singers from the Chapel Royale were recruited to form the core of the orchestra and chorus.

[8] A month before the scheduled concert, he ran into his friend Augustin de Pons in the foyer of the Paris Opera house, the Salle Le Peletier.

[10] A few days before the premiere, Berlioz and his friend Ferrand visited the offices of some newspapers and journals, giving invitations to send a critic and to print announcements of the concert.

[11] The Messe solennelle was premiered on 10 July 1825 at the Church of Saint-Roch in Paris by an orchestra and chorus of 150, conducted by Henri Valentino.

[11] Madame Lebrun of the chorus told Berlioz, "Damn, my boy: now there's an un-worm-eaten O Salutaris, and I defy those little bastards in the counterpoint classes at the Conservatoire to write a movement so tightly knit, so bloody religious.