Aficionados of Western classical music have carved out a niche for themselves in Iran, where cultural expression remains tightly controlled by strict rules imposed after the 1979 Islamic Revolution.
And perhaps surprisingly, musicians in their 20s and 30s perform for overwhelmingly young audiences.
This week, the Tehran Symphony Orchestra, including female musicians in burgundy headscarves on cello, horn, and harp, played works by 19th-century Russian composers for an enraptured crowd in the capital's main concert venue, Vahdat Hall.
A major draw is Shahrdad Rohani, the orchestra's charismatic music director. The Iranian-American composer, musician, and conductor who has led orchestras in the United States and Europe, said he is proud of his homegrown crop of young musicians.
Classical music may not have mass appeal, but Mr. Rohani said in a backstage interview that there's potential for growth, citing a large turnout during a stadium concert last year in Abadan, a provincial city in southwestern Iran.
"Classical music is growing, and as you see, the audience, they are really supporting the arts and classical music," he told The Associated Press during the intermission of Wednesday's sold-out concert.
In four decades of conservative Islamic rule, the space for artistic expression in Iran has expanded or contracted, depending on whether political hard-liners or moderates prevail.
In the first decade after the Islamic Revolution, including the eight-year war with Iraq, pop music disappeared from the public sphere, said Nima Mina of the School of Oriental and African Studies at the University of London.
The Tehran Symphony Orchestra, founded in 1933, continued its work after 1979, he said. Live performances were initially rare, but have increased in number since the 1990s.
Even during periods of eased controls, red lines are enforced.
This includes a ban on female singers performing for mixed audiences, considered "haram," or religiously forbidden. In February, female guitarist Negin Parsa sang a solo during a concert by pop singer Hamid Askari. The authorities cut her microphone, and Mr. Askari's permission to perform was briefly suspended.
A music cafe in downtown Tehran complies with the ban on female singers during live shows, but not when playing records. On a recent afternoon, a blues recording featuring a soulful female vocalist played in the background, as customers sipped coffee.
"Authorities rarely challenge the playing of recorded music in the cafe, and mainly argue about the hijab issue," said waitress Nillofar Dailami, 29, referring to the headscarf all Iranian women are required to wear. Ms. Dailami also professed a love for classical music as a result of her study of guitar.
These days, the influence of hard-liners appears on the upswing again as moderates find themselves on the defensive because of the seeming collapse of the 2015 nuclear deal they negotiated with world powers.
The U.S. walked away from the deal a year ago, instead embarking on a "maximum pressure" campaign against Iran, including unprecedented economic sanctions.
The sanctions have hurt ordinary Iranians, sending prices for staples and consumer goods soaring and weakening the local currency, while raising the specter of war with the U.S.
For Tehran music lovers, events like Wednesday's concert on the main national stage next to the Russian Embassy offers a momentary escape from reality.
"It is little moments that build up your life in the end," said Shafa Sabeti, a 36-year-old architect whose business has suffered as the result of the economic downturn linked to the U.S. sanctions. "Public spaces have gotten more crowded recently. People are just living the moment – maybe it's some coping mechanism."
Yet tensions and fear of escalation are a "major big black cloud hovering over the country," he said.
Wednesday's concert featured works by Russian composers Alexander Borodin, Sergey Rachmaninov, and Nikolai Rimsky-Korsakov.
The audience was entranced.
There was no fidgeting or coughing. A young couple in the balcony held hands. A woman nearby recorded the concert on her iPhone. Mr. Rohani, the conductor, was greeted by loud applause and addressed the crowd several times, including announcing details about an upcoming concert.
"I love the work of Rohani," said concert-goer Ali Reza, 26, who was introduced to classical music by learning to play the piano. He said most of his friends prefer other styles of music, including rock and pop.
Some said there's a generational divide, with older people tending to prefer traditional Iranian music.
"There is a lot of interest in Western culture among the young urban middle-class population," said Mr. Mina, portraying it as pushback against the lifestyle and artistic expression promoted by the authorities.
He said that since the 1940s, Tehran's music conservatory has provided a steady supply of musicians, including those who later join the Tehran Symphony Orchestra.
One of the graduates of the conservatory, violinist Ed Nekoo, spent 10 years in the Los Angeles area but returned home to care for his mother.
He said he misses the exchange with peers abroad and complained of the lack of foreign music teachers.
"We have to learn the music by ourselves," said Mr. Nekoo, 44.
Still, he's optimistic.
"Our audience is so young," he said. "That's what I like about classical music."
This story was reported by The Associated Press. Associated Press writer Nasser Karimi in Tehran, Iran contributed to this report.