NEW YORK - Last year, it took 275,000 bright pink roses to adorn the Metropolitan Museum of Art for the Met Gala, the biggest night in fashion and one of the biggest concentrations of star power anywhere.

It remains to be seen how the museum’s Great Hall will be decorated come the first Monday in May, but one thing is not in question: those entering it will look spectacular. The theme centers on the late designer Karl Lagerfeld, who made an indelible mark on luxury fashion in his long career at Chanel, Fendi and elsewhere. It is a theme not without controversy — Lagerfeld was known for contentious remarks about everything from #MeToo to curvy bodies.

Want to know what to expect as the big day approaches? Not to worry. We’ve dusted off our annual guide for you here, with some key updates.

What is the Met Gala?

It started in 1948 as a society midnight supper, and wasn’t even at the Met. Fast forward 70-plus years, and the Met Gala is something totally different, one of the most photographed events in the world for its head-spinning red carpet — though the carpet isn’t always red.

We’re talking Rihanna as a bejeweled pope. Zendaya as Cin- derella with a light-up gown. Katy Perry as a chandelier morphing into a hamburger. Also: Beyoncé in her “naked dress.” Billy Porter as an Egyptian sun god, carried on a litter by six shirtless men. And Lady Gaga’s 16-minute striptease. And, last year, host Blake Lively’s Versace dress — a tribute to iconic New York architecture—that changed colors in front of our eyes.

It’s important to note that the party has a purpose — last year, the evening earned $17.4 million for the Met’s Costume Institute, a self-funding department. Yes, that’s a heckuva lot for a gala. It also launches the annual spring exhibit that brings hundreds of thousands of visitors to the museum.

But it’s the carpet itself that draws the world’s eyes, with the guest list — strategically withheld until the last minute — featuring a collection of notables from movies, music, fashion, sports, politics and social media that arguably makes for the highest celebrity wattage-per-square-foot of any party in the world.

Is there always a theme?

Yes. As mentioned above, the theme is Karl Lagerfeld, and the exhibit, “Karl Lagerfeld: A Line of Beauty,” looks at “the designer’s stylistic vocabulary as expressed in aesthetic themes that appear time and again in his fashions from the 1950s to his final collection in 2019.” Once again, it has been created by the Met’s star curator, Andrew Bolton.

Does everyone follow the theme?

Not really. Some eschew it and just go for big and crazy. But expect some guests to carefully research the theme and come in perfect sync. It was hard to beat the carpet, for example, when the theme was tied to “Heavenly Bodies: Fashion and the Catholic Imagination” and Rihanna came as the pope, Zendaya channeled Joan of Arc, and Perry navigated the crowd with a set of enormous angel wings. For Lagerfeld, the clothes may be a bit more, er, down to earth.

How much is a ticket for the gala?

Wrong question. You cannot just buy a ticket. The right question is: If I were famous or powerful and got invited, how much would it cost?

If I were famous or powerful and got invited, how much would it cost?

Well, you may not have to pay. Generally companies buy tables. A fashion label would then host its desired celebrities. This year, the cost has gone up, as it does every few years due to rising expenses: It’s now $50,000 for an individual ticket, and tables start at $300,000.