For its final concert program of the 2015-16 season, the Orchestre Symphonique de Montréal was on proverbial steroids to tackle Britten's mighty War Requiem. Massed across the stage, the choir stall and even an upper balcony, the band and its resident chorus, as well as guest singers from far and wide, delivered a performance that thrillingly balanced the monumental and the ethereal.

The War Requiem was composed for the 1962 consecration of Coventry Cathedral, whose predecessor was destroyed during World War II. Like many before him, Britten used the Latin text of the Catholic Mass for the Dead, but interspersed it with several poems from the World War I battlefront by Wilfred Owen. While it was scored, in part, for a boys' choir, the OSM instead welcomed Princeton High School Women's Choir. It was these young New Jerseyites who were up in the gods, producing a suitably angelic sound – sweet, crisp and slightly distant – under the guidance of Vincent Metallo.

Otherwise it was the OSM's chief conductor, Kent Nagano, directing the massed musical force: baritone, tenor and their accompanying chamber ensemble to his left; OSM Chorus, organist and soprano on high; and in a full 180 degrees before him, the orchestra, which surely included at least a few players from the B team. The number of percussionists alone was a rare sight, striking their full arsenal, from gongs and bells to the whip, with dramatic effect.

Though it's a work of high drama, and the musicians exceeded his field of vision, Nagano was extraordinarily restrained, physically speaking. His merest gesture was usually sufficient, and even for passages of great tempest, such as the Sanctus movement's crescendos, he seemed to sculpt sound rather than try to bend it to his will. These fortissimo tempests were thrilling moments of controlled power and gravitas, notable for the percussionists' exciting rumpus and the rich mass of strings, but the unaccompanied pianissimo of the OSM Chorus was breathtaking. Many times, including the concert's final plea for peace, it was as if a hundred voices were united in a single, exquisite whisper.

The soloists were also excellent, particularly American soprano Catherine Naglestad, who sang with superb clarity and control; her swooping, sorrowful sighs, weaving in and out of the chorus during the Lacrimosa, were a highlight of the evening. English tenor Ian Bostridge displayed lovely tone and diction, while the baritone of Canadian Russell Braun, who replaced an ailing Thomas Hampson, was warm and robust. Whether singing solo or as a duo, these gentlemen were able to turn Owen's poetry into theatre with their expressive voices alone.

Britten's War Requiem has had quite a run in recent years thanks to various anniversaries (the work's 50th, 70 years since the end of World War II, the centenary of both the Great War and Britten's birth), making the OSM seem rather tardy. However, this opening-night performance not only demonstrated the work's timeless wonder and pathos, but was so powerful, so nuanced and beautiful, that even concertgoers thoroughly familiar with the work may have felt like they were hearing it for the first time. An emphatic, even ecstatic end to the OSM season.