Famous British composer Benjamin Britten, left, and Russian cellist Mstislav Rostropovich after a performance at the Moscow Conservatory in 1964. (ASSOCIATED PRESS)

Benjamin Britten is hard to pin down.

●His music has been wildly popular; his music has been neglected. He has been branded as reactionary by some. But to more conservative listeners, his music still sounds too contemporary.

●He is one of the most important opera composers of the 20th century, but this year, which is his centennial — he would have been 100 on Nov. 22 — he has been slightly overshadowed by the bicentennials of Giuseppe Verdi and Richard Wagner.

●During his lifetime, he was celebrated: the recording of his “War Requiem,” which had its premiere in 1962, sold 200,000 copies. But the musical establishment tended to find him — a composer who, in the age of serialist techniques, electronic music and John Cage, chose to write melodic, tonal operas and church canticles for children — unserious.

“It may turn out,” wrote Harold C. Schonberg in the New York Times, reviewing “War Requiem’s” 1963 American premiere at the Tanglewood Music Center, “that ‘A War Requiem’ will not, in the long run, have staying power because of a certain obviousness.”

British composer Benjamin Britten conducts a concert performance of his opera, Gloriana, in London, on Nov. 20, 1963. Britten’s ’War Requiem’ is getting two separate performances this month. (Laurence Harris/AP)

On the most obvious level, Schonberg was wrong. “War Requiem” resurfaces often, is still hailed as a masterpiece and is getting two separate performances this month in the Washington area alone: the Washington Chorus’s at the Kennedy Center on Sunday and the Baltimore Sym­phony Orchestra’s in Baltimore and at Strathmore from Nov. 14 to 16. (The Washington Chorus’s recording of its 1995 performance, released in 2000, even won a Grammy.)

But “War Requiem” is a contradictory piece, and somewhat anomalous in the British composer’s canon: big and bombastic in an oeuvre characterized by nuance, subtlety and gently shifting emotions. So the charge of obviousness has a ring of truth, as well.

As to “staying power,” it could be asked of Britten’s work as a whole.

“Peter Grimes” and, to a lesser extent, “Billy Budd” and “The Turn of the Screw” have never left the repertoire, but much of his other work remains in the category of curiosity, and much has been undeservedly neglected. Julian Wachner, who leads both the Washington Chorus and the music program at New York’s Trinity Church, is immersing himself in Britten this fall: in addition to the “War Requiem” in Washington, he is doing a festival in New York of all of Britten’s non-operatic work — 90 pieces, many little known.

“The question is, Why isn’t Britten a mainstay of the chamber music repertory?” Wachner says. “People are going away [from the Trinity concerts] going, ‘Oh my God, I had no idea,’ and the players, too.”

“Maybe after this anniversary, his music will be played more,” says Marin Alsop, the music director of the BSO. “There’s so much of it that doesn’t get to the concert hall.”

“War Requiem” does remain in the concert hall, imposing because of its message, and because of its scale. It’s a massive work: nearly 90 minutes, involving two separate orchestras (a full orchestra and a chamber orchestra), an adult chorus, a children’s chorus and three vocal soloists. Commissioned for the reopening of Coventry Cathedral, nearly two decades after its destruction by German bombs, the piece is conceived as a kind of play-within-a-play: the traditional Latin text of the Requiem mass, sung by the chorus and soprano soloist and accompanied by the full orchestra, is interleaved with poems by Wilfred Owen about the horrors of World War I, sung by the two male soloists and accompanied by chamber orchestra.

“You have an entirely different vocabulary for the big orchestra and choir pieces,” Alsop says, and the chamber-orchestra sections. “You have the traditional Requiem mass, but the ground underneath you is very shaky harmonically, then you go into chamber orchestra sections which, while very contemporary, are far more tonal. I love that juxtaposition.”

What Schonberg called “obviousness” was generally one of Britten’s strengths: in common with some other great opera composers, he had an emotional directness that can border on naivete.

This comes out strongly in “War Requiem,” which is a piece with a mission: it doesn’t want anyone to miss the message. Britten was a pacifist, a conscientious objector — something that drew criticism in the early days of World War II, when his initial response to the gathering storm clouds in Europe was to leave England altogether. “War Requiem” was his chance to make a clear antiwar statement: memorializing the devastation of World War II with poems about World War I, premiered at the height of the Cold War. To symbolize the advent of peace, Britten cast soloists from three once-hostile nations: the British tenor Peter Pears (Britten’s life partner), the German baritone Dietrich ­Fischer-Dieskau and the Russian soprano Galina Vishnevskaya. But the Russians prevented Vishnevskaya from leaving the country at the last minute, thereby emphasizing not the cessation of hostilities, but their tacit continuation.

Britten’s goals also had a sociological component. His many works for children’s chorus, chamber opera ensemble and adult chorus address the practical challenges of getting music out into the community, and “War Requiem” includes all of these forces.

“I love for us to be able to involve so many different segments of the community,” Alsop says. “It makes it a much more communal experience, and I think it enhances that kind of spiritual quality that people get from belonging to a spiritual community.”

“What I love about Britten is that he doesn’t write stupid music for kids,” Wachner says. “He writes music that they have to work their [tails] off to learn, but they can learn it.”

Wachner, a composer himself, is intrigued by what he refers to as the limitations of Britten’s technical palette. “There’s not so many ways [Britten] does compose,” he says, “but he’s able to express all these different stories, feelings, emotions within a rather restricted palette of compositional technique.” He notes the way certain passages of Britten will evoke unrelated moments in other works, but be used to completely different effect.

Britten is one of the greatest composers: lyrical, wise, distinctive, unique. But “War Requiem” does not necessarily draw on those particular strengths. This kind of grand canvas was never quite natural to a composer who was a master of emotional nuance, of chamber opera, of art song, and who by the 1960s was favoring increasingly spare musical textures.

“War Requiem” was, in a sense, a return to an earlier mode, as if shouting intimacies into a megaphone; it trumpets at every step exactly what it is doing. Performances of the work can leave you feeling slightly bludgeoned; in lieu of characters, we have here the blunter emotions of pain and sorrow and anger. The men are sorrowful protesters; the soprano is, in Wachner’s words, “an angry angel.” There is no arguing with anything that the piece is saying, and it says it insistently.

It is this that Schonberg was referring to when he questioned the work’s ability to endure. In a sense, “War Requiem” prevails in part because of its extra-musical components, all of the neat stuff it offers, its always-timely message. “It’s such an important piece sociologically and politically,” Alsop says. “It can conjure up that entire decade of our shared history.”

In short, it’s a work that reflects its place, its time, its history. It may not be Britten’s greatest work, but it is certainly one that makes itself heard.

War Requiem

The Washington Chorus’s performance of “War Requiem” will take place at the Kennedy Center Concert Hall at 7:30 p.m. Sunday. The Baltimore Symphony Orchestra's performance will take place at Strathmore on Nov. 16 at 8 p.m., after performances at Meyerhoff Symphony Hall in Baltimore on Nov. 14 and 15. A bonus for Britten fans: on Nov. 22, Britten’s birthday, the Cantate Chamber Singers will start an all-Britten season with a birthday tribute concert.