Audra McDonald, a ‘royal’ cellist, a social media opera — and 150 carpenters hammering. All this fall in classical music.

A strange thing happened on the way to classical music’s irrelevance. It became relevant.

Many of us never believed it could ever really lose its punch. What no one saw coming, though, was just how severely society would change around it. We need classical music, but what do we need it for?

Is it a tool for raising consciousness about social justice and the changing climate? Or safe haven from the painful drumbeat of alarming news and the amplifying effects of social media?

This fall brings particularly persuasive arguments for concerts of several strains. A late-season visit by the Tallis Scholars provides a peaceful sonic canvas for contemplation. The Philly Pops plays the score to The Nightmare Before Christmas live to screen in October, offering a nice 76 minutes of pure escapism.

Singing City Choir, on the other hand, makes its social-justice lineage clear in a fall concert with Lyric Fest of works about “journey and diaspora, welcome and belonging,” and then a holiday program focusing on Philadelphia as an immigrant city.

“It’s absolutely incumbent on us to somehow through music reflect what’s going on in the world around us,” says Matías Tarnopolsky, president and CEO of the Philadelphia Orchestra, which is increasingly exercising its social conscience. “That does not mean that the music the orchestra plays can’t be a sanctuary, but at the same time it can be a catalyst.”

The orchestra this season highlights women in music — especially composers — at a topical time. Its focus on social and environmental issues will only increase next season, he said.

But how much can classical music really be expected to nudge humanity? The idea that any piece of music can impart empathy or decency, much less leave listeners with a sudden regard for the rule of law, civil liberties, or democracy itself, seems slippery.

“No single concert is going to change the world,” says Jeffrey Brillhart, artistic and music director of Singing City Choir, which has made social justice core to its identity since its founding in 1948 as a racially integrated choir. “But I think if audiences can be sensitized to the humanity rather than to labels, if they can be sensitized to our commonalities, then people will walk out of a concert and may change their opinion about who to vote for, or it may cause people to do more more research. I have to believe that is happening.”

In any case, aren’t many concerts preaching to the converted? Audiences generally self-select into concerts with messages they are predisposed to hearing. But there is great value there, too. A couple of hours in the company of a crowd that shares your reality braces you to go back into a world where that reality sometimes seems in short supply.

Audra McDonald with the Philadelphia Orchestra (Sept. 18, Verizon Hall). Some might argue that the Philadelphia Orchestra should have been starting this season with McDonald all along. Superstar Placido Domingo had been slated to appear at the orchestra’s opening night gala, but following allegations of sexual misconduct published in an Associated Press article last month the orchestra quickly pulled its invitation. The orchestra’s 120th season as a whole focuses on women in classical music, and yet engaging McDonald under these circumstances is not only emblematic of the moment and a movement. She is powerful artist whose incredible expressive range has long been a perfect fit for the ensemble. (215-893-1999, philorch.org)

O19 Denis & Katya (Sept. 18-29, Suzanne Roberts Theatre). Opera Philadelphia’s O19 festival continues the company’s push into new work with the premiere of this chamber opera. Scored for two singers and four cellists with music by Philip Venables and a libretto by Ted Huffman, the piece is based on the 2016 incident of two Russian teenagers who streamed live on social media their tragic standoff with police. The O19 festival also includes company premieres of Prokofiev’s The Love for Three Oranges, Handel’s Semele, and more. (215-732-8400, operaphila.org)

Playing a Debt of Gratitude (Sept. 23, various locations). String quartets in North Philadelphia and Collingswood, a horn sextet in Grays Ferry, a low brass trio at a retirement community in Bryn Mawr — these are the expressions of thanks from musicians of the Philadelphia Orchestra to its public when players fan out for a day of audience appreciation concerts. More than 30 chamber ensemble performances are slated in the city and suburbs for the fifth annual iteration of the event. (pomusicians.org)

Spit Spreads Death: The Parade (Sept. 28, from the Navy Yard to Dilworth Park). Music, choreography and floats are elements in an unusual parade produced by U.K-based artist collective Blast Theory commemorating the 1918-19 influenza outbreak that killed thousands in Philadelphia and elsewhere. For it, New York composer David Lang has written music prerecorded by the Crossing choir — a “musical motto” based on a health manual from the time of the epidemic, and melodies using names of Philadelphia victims and healthcare workers. “I am named after a relative of blessed memory who died in that epidemic, so I thought I had to be a part of it,” said the Pulitzer Prize-winning composer. David Avery Lang is named for his father’s cousin, Daniel Abraham Leibowitz, who had just arrived in America from Lithuania when World War I broke out. At 18, he enlisted in the army and was sent to boot camp in Georgia, where he got sick and died. “He meant a lot to the family, because he was living proof of the deep and real commitment of the new immigrants to the United States,” said Lang. "His enlistment meant that they would belong here, and his death rattled them all so much that they were still mourning him when I was born, 38 years later.” (spitspreadsdeath.com)

First Friday Concerts (Oct. 4, Christ Ascension Lutheran Church, Chestnut Hill). The concept for this new series is a concert on the first Friday of the month from September to June, an hour of music starting at 6:30 p.m., with tickets priced at just $10. Organizer Michael Locati aims to bring local talent to Chestnut Hill, and the October concert features cellist Andres Sanchez, a recent Curtis Institute graduate, in works of Bach, Lutoslawski, and Gaspar Cassado, among others. (firstfridayconcerts.org)

Two Cellists in a Parking Lot. (Oct. 5, 990 Spring Garden St.). Spaces in and around the Rail Park, a post-industrial patch of lower North Philadelphia taking shape as an urban park, are the setting for Site/Sound, a fall festival of free music, dance, performance art, film, installations, and more slated for Oct. 5-19. One particularly promising event brings together Thomas Kraines, cellist in the Daedalus Quartet, and Syrian-born cellist and composer Kinan Abou-afach in works by Abou-afach that draw on both classical Western and Arab music styles. They play in a parking lot — next to a viaduct section planners hope to capture for a future phase of an expanded Rail Park project. (215-685-0750, muralarts.org/sitesound)

Singing City Choir and Lyric Fest (Oct 5, Haddonfield United Methodist Church; Oct. 6, Philadelphia Episcopal Cathedral). With works by Schubert, Carlos Guastavino, Poulenc, Lee Hoiby, and others, the choir is joined by three vocal soloists and pianist Laura Ward in a program about migration and immigration. Longtime music and artistic director Jeffrey Brillhart conducts. (267-519-5321, singingcity.org)

The Crossing, Gavin Bryars Premiere (Oct. 13, Presbyterian Church of Chestnut Hill). Billed as the English composer’s most substantial work for unaccompanied choir, the concert-length A Native Hill, based on writings of Kentucky poet, novelist, essayist, farmer, and activist Wendell Berry, receives its world premiere. Donald Nally conducts. (215-436-9276, crossingchoir.org)

The Nightmare Before Christmas (Oct. 24 and 25, Met Philadelphia). Tim Burton’s 1993 stop-animation film has had a staying power that seems surprising until you hear how finely contoured the music is to the emotion of the story. It’s a lot about the excruciatingly beautiful chord progressions, not to mention inventive orchestrations. So it should be a workout for the Philly Pops and an extreme pleasure for listeners when the Met Philadelphia’s house orchestra takes on the Danny Elfman score live to screen with Stuart Chafetz conducting. (800-745-3000, phillypops.org)

Music for 150 Carpenters (Nov. 7-March 15, Ursinus College). To note Ursinus College’s 150th anniversary, Berlin-based artist/composer Douglas Henderson will compose on site at the Berman Museum of Art an “immersive sound performance” utilizing 150 workers, 150 sawhorses, 150 hammers, and 10,000 or so nails. The sounds of construction will form a “tonal murmur,” captured on video and audio to be replayed continuously in the gallery through March. (ursinus.edu/berman)

Black Violin (Nov. 8, Academy of Music). Violist Wil Baptiste and violinist Kev Marcus keep returning to Philadelphia in ever-bigger venues — World Café Live, then the Merriam, and now, with this Impossible Tour appearance, the Academy of Music. The Kimmel has the high-energy duo as part of its jazz series, but classical, hip-hop, and rock were the primary elements in the mix heard in their 2015 World Café Live performance. (215-893-1999, kimmelcenter.org)

L’Orchestre Métropolitain de Montréal and Joyce diDonato (Nov. 24, Verizon Hall). The mezzo’s richly-colored sound will be joined by conductor Yannick Nézet-Séguin when the Philadelphia Orchestra presents its music director with his other, northernmost orchestra. DiDonato sings Mozart’s “Ch’io mi scordi di te? ... Non temer, amato bene” with Nézet-Séguin taking the piano part, and “Parto, ma tu ben mio” from La clemenza di Tito. After intermission, Nézet-Séguin leads his fellow Montrealers in Bruckner’s Symphony No. 4. (215-893-1999, philorch.org)

An Organ and Brass Christmas (Dec. 1, Verizon Hall). Organist Peter Richard Conte and brass from the Philadelphia Orchestra match rumble with silvery fanfare in Christmas repertoire. Newly minted Philadelphia Orchestra assistant conductor Erina Yashima presides over the seasonal cheer. (The full orchestra does not perform at this concert.) (215-893-1999, philorch.org)

Tallis Scholars (Dec. 5, Church of the Holy Trinity). The program includes Poulenc, Byrd, Messiaen, Allegri, and Tallis when this much-loved a capella ensemble of 10 voices visits with conductor Peter Phillips. For those who used to treasure the otherworldly joining of peace, place, and time of year that used to come with Anonymous 4′s annual Philadelphia concert, this experience seems a worthy successor. (215-569-8080, pcmsconcerts.org)

Cellist Sheku Kanneh-Mason and pianist Isata Kanneh-Mason (Dec. 17, Perelman Theater). The 20-year-old British cellist, celebrated for playing at the wedding of Prince Harry and Meghan Markle, makes his Philadelphia debut with one of his sisters in Beethoven, Barber, Lutoslawski, and Rachmaninoff. The recital is sold out, but Philadelphia Chamber Music Society regulars know that persistence almost always pays off. (215-569-8080, pcmsconcerts.org)

... And mark your calendar for these early 2020 standouts (various dates and locations). The Philadelphia Chamber Music Society stages its Emerging Voices project (Jan. 13-24), a festival of concerts and other events co-curated with tenor Nicholas Phan exploring national identity through song. The Academy of Music 163rd Anniversary Concert and Ball is Jan. 25, special guest yet to be announced. And #GLASSFEST, a three-week festival of works by Philip Glass at Penn’s Annenberg Center, starts in February.