At the Mann Center soon, you'll be able to feel the death-chill of Harry Potter's dementors on the back of your neck as a live orchestra plays the John Williams score. On another night, you could happen upon a fresh Curtis Institute of Music graduate with a big piano personality in Gershwin. And if you listen for a central message rising from this summer's classical season at the Mann, you might hear the wall between classical and other genres crumbling.

In all, 10 concerts in Fairmount Park this summer employ orchestral music — though perhaps only one, the Philadelphia Orchestra's annual all-Tchaikovsky concert, follows a strictly classical format.

The focus is on Leonard Bernstein and his "advocacy for social justice, particularly the way in which he leveraged the platforms that he had in order to extend opportunities to a diverse group of artists," says Nolan Williams Jr., artistic director of the Mann's annual festival that programs at the intersection of art and social issues.

Admittedly, many presenters and orchestras are celebrating Bernstein in the centenary of his birth, says Mann president and CEO Catherine M. Cahill. But the Mann didn't want to be "just another vessel to replicate what others were doing," and so it sought to "bring the social-justice warrior side of Bernstein to life," she says.

The Mann's offerings will once again spill beyond Fairmount Park into schools, churches, and other venues, with programs and concerts.

A core offering, though, is still the Philadelphia Orchestra, which makes a handful of appearances at the Mann: for the Tchaikovsky Spectacular (July 17), in the John Williams score for Star Wars: A New Hope with film (July 20), for an Eagles-theme concert with NFL Films (July 24), with more John Williams in the score to Harry Potter and the Prisoner of Azkaban with film (July 26), and in an all-Gershwin concert with Curtis grad Micah McLaurin in the Piano Concerto in F (July 27).

Chamber Orchestra of Philadelphia takes up the film-score duties in a screening of Jaws (June 2) and ventures into the rock-opera realm backing up Roger Daltrey in The Who's Tommy (June 19). (Online early-bird readers can still make it to the May 26 Philly Pops concert of patriotic tunes.)

Mann Center festival artistic director Nolan Williams Jr.
TOM GRALISH / Staff Photographer
Mann Center festival artistic director Nolan Williams Jr.

The big public centerpiece of the Bernstein festival is a Mann commission from composer Darin Atwater, whose South Side, Symphonic Dances will be premiered July 18 by the Philadelphia Orchestra led by conductor Kensho Watanabe. The new piece is heard alongside Bernstein's Symphonic Dances from West Side Story, Rhapsody in Blue with pianist Stewart Goodyear as soloist and excerpts from other Bernstein works, including On the Town.

"It's the cousin of West Side Story, if you will," the Mann's Williams says of Atwater's new work. "West Side is a euphemism for the 'other' in our community, the immigrant in our community. South Side is a euphemism for the other side of the railroad track, where generally people of color are often found in most major cities, so he's exploring that."

The nine-movement work for full orchestra uses various dance forms to shape a narrative, says Atwater — struggle, racial tensions, eroticism, freedom, and optimism, among them. Rather than Sharks and Jets, he created an abstraction: an oppressive "gang" of racism, media biases, and various inequities. He hopes it's the kind of experience listeners will take with them beyond the concert hall.

"Music and dance should demolish the artificial barriers and constructs we have allowed to divide us," says Atwater. "Great art and great music and dance become a dialogue, an interaction between gender and race and religion, and that is the goal of this piece. If it's just a dance piece for orchestra, I've not done my job. It has to bleed into the community."

Another cousin of a different Bernstein work is a joint effort — of four composers. The Mann Center festival performance Philadelphia Community Mass is to be performed Aug. 11 at Monumental Baptist Church at 50th and Locust Streets. Scored for choir, percussion, piano, guitar, bass guitar, and woodwinds, it can be thought of as a loose-knit meditation on Bernstein's peculiar work of spiritual theater music.

Composers Rollo Dilworth, Ruth Naomi Floyd, Jay Fluellen, and Evelyn Simpson Curenton have a lot of latitude, says Williams. "They may actually take what Bernstein wrote and simply arrange it. In some cases, they may take motifs from what he wrote and use that as inspiration. They may take the melody and reset the melody.

"But the idea is to explore what he was trying to explore, which was the meaning of faith and the relevance of faith in our times, and they are being guided in their musical compositions by genres that define African American sacred liturgy," he says. "There are hymns, spirituals, gospel both traditional and contemporary, elements of jazz and the blues. All of that will come into their compositional style."

Leonard Bernstein in 1973.
Allan Warren
Leonard Bernstein in 1973.

The Mann uses its annual festival to make connections with the African American community. What, then, was so compelling about a dead, white classical composer and conductor as the focus for this year?

Williams points to statements like the one Bernstein and his collaborators made in On the Town by casting, during World War II, a Japanese American dancer in a lead role, and by putting black and white cast members side by side. African American conductor Everett Lee led the show after a certain point.

"At that time, even the U.S. military wasn't integrated," said Williams. "It was a very clear statement he was making. He was using the platform he had to push America toward her promise."

Later, after Bernstein took over the New York Philharmonic, "there were African American musicians who couldn't get opportunities in other places who were able to perform with the New York Philharmonic and even record. That's because Bernstein opened those doors."

Composer Darin Atwater
Jordan August
Composer Darin Atwater

The Mann is using Bernstein as a bridge with students at KIPP DuBois Collegiate Academy, where Atwater has already spent several months working on a songwriting workshop around the Bernstein musical 1600 Pennsylvania Avenue.

Students will write their own pieces, spanning several genres, and will take their works into the recording studio.

1600 Pennsylvania Avenue, which had tryouts in Philadelphia and Washington,  was a box office failure in its 1976 Broadway premiere. It explored racial injustice through the lives of White House occupants — both  presidents and servants.

Williams says that although the show was a flop,  Bernstein considered it  one of his greatest accomplishments artistically. "I argue that in large part it was a commercial failure because in 1976, when this piece was premiered, the country was just not ready to have a conversation about race relations in America. Sadly, 42 years later, we could argue that the country still is not ready to have a conversation about race relations."

If Bernstein bridged racial divides, he also, through stylistic fluidity in his own music, made the case that the bold line between classical and pop music, concert hall and church (think of the Mass), represented a construct that was not only unnecessary but also limiting. This idea plays out vividly at the Mann this summer, where orchestral forces meet film, rock opera, Broadway, sports (in the show with NFL Films), and even games when the Kingdom Hearts Orchestra visits on Aug. 2.

Viewed through the lens of today's orchestral panoply, Bernstein seems more prescient than ever.

"It's amazing that orchestras love playing the "Symphonic Dances" [from West Side Story) now," says Williams, "but at the time that was really not the most popular music, because there was this sense that he was bringing all of these cultural and folk elements, and how dare you have us sitting here saying,  'Mambo' and snapping our fingers [as the orchestra members are asked to do].

"But he was progressive. And I do think he had his finger on the pulse of something that was very forward-thinking. And you are seeing that now, that orchestras are realizing, particularly in our time, if they want to survive, if they want to gain audiences, they have to follow that model of bringing more fusion into their programming  and into the work that they do."

Tickets and information for Philadelphia Orchestra performances and other Mann Center concerts: 800-745-3000, www.manncenter.org.

There is no charge to attend the Philadelphia Community Mass Aug. 11 at 3 p.m. at Monumental Baptist Church, 50th and Locust Sts., though reservations are suggested. 215-546-7900, www.manncenter.org.