LYNN – It’s the Saturday night after Thanksgiving, and while it’s 20 degrees outside, 150 people are on their feet applauding inside the former Ahabat Sholom sanctuary in Lynn. Now used by Chabad of the North Shore for programming, the old shul has been rocking for the last two hours.

On stage is the conductor of the evening’s mirth, Shulem Lemmer. Shulem, the first ultra-Orthodox singer to sign a major record deal, has led the audience through a mix of Hasidic niggunim, Yiddish standards and pop songs and seems to be just warming up even though he’s just got a couple of tunes to go. He’s been seamlessly moving from Hebrew to Yiddish to English, delivering the likes of “Jerusalem of Gold,” “My Yiddishe Momme” and “Bring Him Home” from the Broadway show “Les Miserables.”

That’s seems a lot to ask for a guy who up until a couple of years ago was working as a marketing director and moonlighted as a soloist at bar mitzvahs and other Jewish gigs in Brooklyn. Shulem first started singing when he 10 at family events, and later joined yeshiva choirs. When he was 13, his sister Tzippy – who died when she was 23 – encouraged him to sing on stage at a family wedding. “She was the first one to put me on stage and I sure hope she would be proud of me today,” says Shulem.

About two years ago, Universal Music executive Graham Parker stumbled upon Lemmer’s YouTube video version of “Chad Gadya,” and sent Shulem an email. The two met for coffee and Parker wanted to know if the vocalist could sing in English. Until then, Shulem’s influences had been mostly Hasidic: Mordechai Ben David, Avraham Fried and the Israeli singer Yaakov Shwekey. Shulem soon signed a record contract, and agreed to sing in English, and learn secular music that most Belz Hasidim never hear – Simon & Garfunkel, Billy Joel, Elton John and Michael Jackson.

Shulem, who is rail thin and wears a simple kippah above his short brown hair and payot, alternately spreads his arms like wings when he sings a chorus and then clasps his hands in prayer when he completes a song’s final note. He wears a long black coat, a crisp white shirt and his soft brown eyes sparkle when he engages with the audience. As his piano player taps soft notes in the background, Shulem speaks from the stage like a host who has a crowd of new friends over for chicken soup.

It had already been a long weekend for Shulem and his week ahead was booked with gigs at City Winery in Boston and concerts in Chicago and Los Angeles. And the night before the Lynn concert, Shulem had led Kabbalat Shabbat services at Chabad in Swampscott. Rabbi Yossi Lipsker, who brought Shulem to Chabad and sponsored the concert, believes Shulem’s voice has the power to uplift souls. “Shulem Lemmer is a sensational artist with an extraordinary story,” says Lipsker. “Hearing him is both spiritually uplifting and hugely entertaining. When the opportunity came up we couldn’t pass on it.”

A few weeks ago Shulem released his album, “The Perfect Dream,” which includes “Avinu Malkeinu,” “You’ll Never Walk Alone” and “God Bless America.” While he once performed before small audiences, Shulem is now in demand to sing the national anthem and “God Bless America” at American stadiums. To date, he’s performed at Fenway Park, Citi Field in New York, the Barclays Center in Brooklyn and at Oracle Park in San Francisco. Married, and a father of three, Shulem has also toured in Israel – where he lived for six years – and played gigs in London, Krakow, Frankfurt, and Zurich.

Two hours into the show, just before the clock strikes 9, he advocates for civil discourse: “At the end of the day as much as we have our differences, we have so much more in common as human beings,” he says, before launching into Billy Joel’s “Piano Man” – a song he learned less than two years ago. He then prepares for an encore, and listens as requests are shouted out from the seats. “Play ‘Free Bird,’” someone pleads, but Shulem settles into Leonard Cohen’s “Hallelujah.”

Soon the lights come on, and fans scramble to take selfies with him and shake his hand. He accommodates each person until the room is empty, and then pulls up a chair and sighs. “My goal is to inspire as many people as possible,” he says, adding that he also has many Christian and Muslim fans. When I ask if he’s surprised about his success, he shrugs and smiles and then talks about gratitude. “I always had a dream but I’ve never been a person who tried proactively to get my career somewhere. It’s all because of Hashem.”