His Requiem, composed in 1837 is a radical setting of the Catholic Mass for the Dead. It is an enormous work, requiring a huge choir, large orchestra and four specially placed ensembles of brass instruments, used to stunning effect. The work is not performed often, but it influenced opera composers Richard Wagner and Arrigo Boito when it came time to announce the presence of divine influence in their operas.
The first section of the Requiem (Kyrie) opens with a series of mysterious, hushed chords. Played in a minor key, this introduction was appropriated by Wagner for the beginning of his final opera, Parsifal. The Parsifal prelude borrows the idea of suspended chords, shimmering curtains of strings and woodwind that seem to "hang" in space, pulling the audience into the work in preparation for a story about sinning, redemption and the revalation of the Holy Grail.
Berlioz encountered Wagner in 1842, and again in 1860 when the younger composer was giving concerts in Paris. Wagner eagerly shared his ideas for the 'music of the future.' (Berlioz referred to Wagner's ideas as 'L'école du charivari'--the "school of mayhem.") In 1858, Berlioz read the libretto of Les Troyens to Wagner. This five-act opera, based on Virgil's Aeneid, was the culmination of Berlioz' life's work. It was not performed in its entirety until 1924.) Neither composer quite understood what the other was doing. But that didn't stop Berlioz' Requiem from exerting influence on Parsifal.
Ideas from the Requiem also show up in Mefistofele (1868) the only completed opera by Italian composer and critic Arrigo Boito. Mefistofele is a setting of Goethe's Faust (which Berlioz set in 1846 as La damnation de Faust.) Boito and Berlioz both made their livings as music critics, and each composer wrote difficult works that met with hostility at first, but were eventually accepted into the repertory.
Mefistofele opens with a scene set in the heavens, depicting the Devil's famous wager with God. The stakes: Faust's soul. God is offstage, represented by singing choirs of angels (also offstage) echoed by huge slablike chords in the brass. This idea of trumpet choirs, echoing back and forth with the main orchestra, shows up in the most famous moment in the Requiem. In the Dies Irae section of the mass, (which depicts God's wrath and the Last Judgement) the brass choirs announce the Tuba Mirum--the blowing of the last trumpet. In both works, the effect is unforgettable.
Watch the Prelude to Parsifal here.
Watch the opening scene of Mefistofele here.
Top: Hector Berlioz. Middle: Richard Wagner. Bottom: Arrigo Boito. All photos from Wikipedia.