The instrumental forces alone demand that we step back and look at Hector Berlioz Grand Messe des morts, Op. 5 (Requiem) a little differently than we might look at another composition -- even another large-scale, theatrical composition -- from the 1830s: in addition to the usual large orchestra and chorus, Berlioz calls for no fewer than 16 timpani and four extra brass choirs! When the French ministry of the interior commissioned a requiem mass from Berlioz in 1837 and decreed that the conservative conductor Francois-Antoine Habeneck would lead the December 5 first performance of the work, they can hardly have had such a thing in mind (nobody had yet ever even conceived of an instrumentation like that before, certainly not for indoor use); but Berlioz, through all his many ups and downs as a composer, was never one to suppress his fiery sense of the dramatic (as fiery as his bright red hair, so the stories go), and, in the end, even Habeneck -- who, according to a not impartial Berlioz, tried his best to ruin the Requiem's premiere -- had to admire the spark of genius and the sheer spunk that it took to put that thing on paper. Today the Requiem is Berlioz's second-most famous work, behind the Symphony Fantastique, though, as one might imagine from its performance requirements, it is not his second-most frequent visitor to the concerthall (or the cathedral, as the case might be).
Berlioz's Grand Messe des morts, scored for orchestra, tenor soloist, and SSTTBB chorus plus the extra forces listed above, is in ten sections and runs in excess of an hour and a quarter. Not all of its music is massive (the extra forces explode onto the scene in the Tuba mirum portion of the Dies irae sequence in No. 2 and then disappear), and indeed much of it is quite intimate -- for example the slender No. 3 Quid sum miser, which immediately follows the outburst in No. 2, or the opening of No. 9 Sanctus, which features the solo tenor. And the Requiem ends in absolute tenderness, the Lamb of God (No. 10 Agnus Dei) having taken away the sins of the world and accepted the dead into a new world, of which we mortals can hear only vague echoes -- timpani strokes left over from the explosive Last Judgment held earlier in the mass, now distant and gentle.