The Jewish Exponent mentioned Mekor’s own band, Moments of Wrong, in its account of this year’s Lag b’Omer festival:

It was finally starting to feel like summer, with temperatures rising into the 90s last week. But it got even hotter on May 26 at Fifth Street and Cecil B. Moore Avenue after the fire marshal arrived and the bonfire could finally be lit.

The Mystic Music Festival, co-sponsored by The Chevra and the Jewish Center of Northern Liberties, brought live music, food and drink and a seriously diverse crowd to a vast vacant lot in Kensington for a celebration of Lag B’Omer.

In case you’re not familiar with Lag B’Omer, which isn’t one of Judaism’s major holidays, here’s a brief primer: It’s an agriculturally based observance that derives from biblical law, which proscribes that an omer — an ancient Hebrew measure of grain — must be offered at the Temple in Jerusalem.

Leviticus reads: “And from the day on which you bring the offering … you shall count off seven weeks. They must be complete.”

For our agrarian ancestors, that seven-week span was customarily a somber time reserved for praying for good weather for the harvest. Today, it’s still a period of cultural restraint: festive gatherings, weddings and even haircuts are prohibited.

There is one exception, though, and that’s the 33rd day of the Omer, aka Lag B’Omer. On this day, dancing, music and parties are encouraged. People get married. Kids play with bows and arrows. There are picnics and field trips. And there are bonfires everywhere — even in Kensington.

Though the Jewish Center of Northern Liberties had been throwing this Lag B’Omer party for 11 years, this was the first time it held the event at this location, a fenced expanse of grass and dirt surrounded by evidence of Philadelphia’s industrial past — and of its vibrant, ever-changing present.

The remains of the old Gretz Brewery, with its iconic smokestack, loom over the lot; directly across the street, a former factory has been converted to loft apartments. Down the street, a craft brewery named for Ben Franklin has taken up residence in the former carriage house and stables of the defunct Theo Finkenauer Brewery. Other old buildings stand in limbo, no longer needed for the Workshop of the World, but not adapted for current use.

The intersection of Fifth and Cecil B. Moore is also notable for its painted concrete canvases. Several walls here are permission walls, meaning the property owners allow and encourage the artwork — and have done so since the 1980s. As a result, the corner is alive with constantly changing, brightly colored images that bring photographers and artists from all over.

A building-length mural of late Latino rapper Big Pun runs along North Fifth Street. It almost seemed as if he was watching, perhaps with some puzzlement, as the Lag B’Omer celebrants queued up for hotdogs and wings.

Rabbi Gedaliah Lowenstein, co-director of the Chabad-affiliated Jewish Center of Northern Liberties, chatted amiably beneath Big Pun’s gaze as he slathered sunscreen on his skin. He said the center started the Lag B’Omer festival when it was looking for a signature event. The minor holiday was the perfect fit.

“It’s fun,” said Lowenstein, “and no one else does it.”

The first year they got about 150 people out to the festival, but it’s become much more popular since then.

“The highest year we got about a thousand people,” he said.

On May 26, the lot quickly filled up with people of all stripes, including Fairmount resident Amanda Leslie and Brewerytown’s Lucy deWahl. Leslie came to support her boyfriend, who was in one of the seven bands playing at the event.

“We’re probably not a good representation [of this crowd],” she said. “I’m Jewish, but I’m not observant. And this is my gentile friend,” she said, gesturing to deWahl, who smiled broadly.

But Leslie and deWahl were actually perfectly representative of a crowd that couldn’t be easily defined. Like the neighborhood itself, the mix of people was diverse: There were families with children, young hipsters with beards and tattoos, men wearing yarmulkes and tzitzit, people speaking different languages.

Neither Leslie nor deWahl had ever heard of Lag B’Omer, but that wasn’t a deterrent.

“This is a fun, weird thing to do on a Thursday night. It’s an interesting use of the space,” Leslie said.

As the band Moments of Wrong played a song by the Talking Heads, Derek Greeley and wife Courtney, who live in Moorestown, N.J., got comfortable in their camp chairs. Greeley, the director of youth engagement at the Reform Temple Adath Emanu-El in Mt. Laurel, N.J., would normally be busy with his youth group, Aefty, on a weekday afternoon. But Thursday he had off, so he and Courtney drove into the city.

“I try to celebrate Lag B’Omer when I get the opportunity,” he said. “And I’m fortunate this year to have that opportunity.”

A band named Shoresh played roots-rock tunes about rebbes, shofars and davening as the fire got larger. Parents were warned to keep their children away from the bonfire’s perimeter or the fire marshal would shut it down.

Lowenstein said it took a long time to get permits for the event — one of which, because of the bonfire, is a “permit to pollute.” But all the waiting seemed to be worth it on Thursday.

Perhaps it was the beginning of a new tradition for Philadelphia’s Olde Kensington.