They should be required listening, those fanfares in Britten's War Requiem -- loud battle cries of trumpets and other brass that rise up out of the piece, which is getting a rare outing this weekend with the Philadelphia Orchestra.

Almost never have fanfares come with less glory. Edged not in noble gilt but in dissonance and remorse, Britten's fanfares stand in judgment of war as man's most pointless invention.

The orchestra has done the stunning War Requiem only once before, in 1993, with Wolfgang Sawallisch in his first season as music director. As big statements go -- music that begs a connection to the current state of world affairs -- this one has only intensified in 2½ decades.

Britten does not preach. He gives the impression of a composer who has assembled disparate forces and allowed the listener to draw her own conclusions. Written in 1961 and scored for two discretely functioning orchestras, adult and boy choirs, three vocal soloists, and organ, the text is a deft weaving of liturgy and World War I poetry by Wilfred Owen. And yet it is a commentary on all wars.

Not many conductors could have managed as much polish as conductor laureate Charles Dutoit did Thursday night. With the appropriately wan-sounding American Boychoir in Verizon Hall's second tier and the Westminster Symphonic Choir in the conductor's circle, Dutoit kept the nearly 200 singers sounding no less directly connected than the dozen instrumentalists in the inner-core chamber orchestra.

This feature is Britten's genius stroke: While the full orchestra generally worked with the choirs, the province of the mini-orchestra, nestled at the front of the larger one, was in the intimacy of solo-vocal material. Part cantata, part lieder recital, it made for the evening's most excruciatingly beautiful peeks into humanity.

Britten's musical language can be harsh, but that only heightens the emotion when he does tug at the heart. He does so often. In the "Dies Irae," where chorus and soprano sing of guilt and mankind being called to account, the life drains out of the music like so much blood. Then tenor enters with sun and "wakes the seeds," and the music shimmers with promise. The sequence is as moving as anything in Bach.

Some hear literal characterizations in the parts for soprano, tenor, and baritone, and Tatiana Pavlovskaya, Steve Davislim, and Matthias Goerne filled out the roles with a specificity that brought you directly into intimate worlds. In doing so, they captured Britten's gift for ambiguities. Can two soldiers transcend national allegiance for a more human one? Is religion a comfort, or does its use here amid the horror of war only point up its own futility?

Britten finds forgiveness, but he doesn't let us off the hook easily -- not at the piece's creation in 1961, and not now.

Additional performance: 8 p.m. Saturday in Verizon Hall, Broad and Spruce Streets. $10-$147., 215-893-1999.