On Thursday night in the West Village of Manhattan, the soulful British balladeer Sam Smith hosted a private party at Julius’, which is known as the oldest gay bar in New York. Friends and fans sweltered inside the tavern, sipping vodka tonics as they waited for a late-night performance by Smith and a rumored special guest, Alicia Keys.

Smith, who uses they/them pronouns, chatted with fans by the worn wooden bar. Standing about 6-foot-7 in Vivienne Westwood platform boots, paired with a tartan kilt and a big belt, the Grammy-winning singer towered above those who asked for selfies.

The gathering commemorated the 10th anniversary of Smith’s debut album, “In the Lonely Hour,” which included the slow-burning anthems “Stay with Me” and “I’m Not the Only One.” Little menus along the bar advertised cocktails named after Smith songs like “Good Thing” (a cosmo) and “Life Support” (a margarita). And they noted Julius’ relevance as a historic site, detailing the events of the 1966 Sip-In, an act of civil disobedience that predated the Stonewall uprising by several years.

With Pride celebrations in full force throughout the West Village, Smith had chosen Julius’ precisely because of its connection to the Sip-In, when members of the Mattachine Society, an early gay rights group, visited Julius’ to challenge bars that would not serve gay customers. When the activists were refused service after intentionally revealing that they were “homosexuals,” the incident made news, attracting the attention of the Commission on Human Rights.

“Why did I pick Julius’?” Smith said, leaning down to a reporter. “Because I’ve never felt more safe in any other bar in the world than here.”

As servers in Julius’ T-shirts pushed through the crowd offering trays of burgers, the drag artist Lady Bunny played a DJ set. Helen Buford, the owner of Julius’, remarked on the responsibilities of running a historic gay bar.

“We need all the attention we can get, because historic gay bars in New York need to survive,” she said. “Whether that bar is Henrietta Hudson or the Cubbyhole or even Stonewall. What Sam is doing here tonight really helps us. This also is our busiest time of the year. Pride is our Christmas.”

A few patrons reflected on Smith’s artistic evolution over the last decade, from a British import who was initially packaged as a crooning alternative to Adele to a bona fide pop star who gyrated to “Unholy” onstage at the Grammys wearing shiny red boots and a top hat with devil horns.

The influencer Dylan Mulvaney fondly remembered the release of “In the Lonely Hour.”

“I used to dance to all the songs on that album when it came out,” she said. “As someone who also embarked on their own gender journey, it has been great to watch Sam evolve ever since as an artist, and they’ve been an inspiration to me.”

Brendan Byrnes, an actor and director, married his husband at Julius’ in 2014.

“I feel Sam was pigeonholed at first by what the record industry thought they should be,” Mr. Byrnes said. “But 10 years later, Sam knows exactly who they are. Sam is now a queer icon.”

“My husband and I were just talking with Sam by the bar, and I told them how we got married here,” he added. “We love that Sam loves Julius’ as much as we do. It’s not on the map as much as Stonewall is, but that’s also what makes it wonderful.”

Andrew Tess, a nightlife photographer, recalled the album’s hold on him.

“When it came out, Sam was exploring queer moments of love in those songs, but in a subtle way,” Mr. Tess said. “But the world has changed in 10 years, and the way we communicate queer love has also changed. I think Sam is a proponent of why that happened. It’s beautiful to see how they keep evolving, just like Bob Dylan or Madonna.”

As midnight approached, a black S.U.V. appeared outside of Julius’. Ms. Keys stepped out and entered the bar to join Smith on a tiny stage for “I’m Not the Only One.” The sweaty audience included Prabal Gurung, Kim Petras and Smith’s partner, the designer Christian Cowan.

As Smith sang, with Ms. Keys providing piano accompaniment, the crowd chanted the familiar chorus.

You say I’m crazy

’Cause you don’t think I know what you’ve done

But when you call me baby

I know I’m not the only one.