Wendy Mazur said her “jaw hit the floor” when she saw her favorite pop singer, Goldford, walk out with his guitar during her first dance with Jerry Bedwell at their wedding in April 2022.

The couple considered the ballad “Upside Down” their song and had made it the theme of their reception at City Winery in Nashville. Their guest book, for example, was a custom puzzle of the “Upside Down” cover art.

Mr. Bedwell, 55, who works in information technology, surprised Ms. Mazur, 47, by hiring the musician to perform the love song live.

“I still get teary-eyed thinking about what Jerry did for me, making Goldford part of our wedding day,” said Ms. Mazur, a technology consultant and freelance writer. “What a loving surprise he gave me.”

Instead of opting for a simple recording for the first dance or a playlist for the after-party, some couples are splurging on surprise performers — Broadway stars, singer-songwriters, Grammy Award-winning acts — for their weddings, treating friends and family members to unexpected, meaningful experiences.

Celebrity performances at weddings have recently made headlines: In April, Ankur Jain, the chief executive of Bilt Rewards, a loyalty rewards company, arranged to have the singer Robin Thicke and the electric violinist Lindsey Stirling for his wedding in Cairo to Erika Hammond, a wrestler with World Wrestling Entertainment.

For Anant Ambani and Radhika Merchant’s recent pre-wedding celebration in Jamnagar, India, Rihanna took the stage, as well as the Bollywood star Shah Rukh Khan. Mariah Carey sang her top hits for the fashion retail executive Umar Kamani and the model Nada Adelle at their wedding reception in Antibes, France, in May.

“A surprise headliner is not something the majority of guests have ever experienced before, even if they have been to dozens of weddings,” said Tracy Taylor Ward, an event planner in New York who most recently worked with Flo Rida for a wedding performance. “It’s incredibly memorable and fun.”

Booking a headliner isn’t cheap: The vendor can cost anywhere from thousands of dollars to $3 million, Ms. Ward said. A top name like Rihanna or Lady Gaga could fetch up to $5 million, said Josh Friedman, the owner of Élan Artists, an entertainment services company in New York that books performers for weddings, among other events.

More couples have requested well-known musical acts over the last decade, Mr. Friedman said, with a greater spike after the Covid-19 pandemic. Popular requests, he said, include John Mayer, John Legend, Flo Rida, Maroon 5, Zac Brown Band and Andrea Bocelli.

Marshall Weinstein, who runs the event production agency SET Artist Management, worked with Ms. Ward to surprise his wife, Ariel Moses, with a performance by one of her favorite artists, Mr. Cheeks, at their wedding reception in February 2016 at Gotham Hall in New York.

He thought it would be a playful “throwback moment” to have Mr. Cheeks rap his 2001 hit, “Lights, Camera, Action.”

“The look on her face was priceless — that’s why I did it,” Mr. Weinstein said of Ms. Moses, a publicist. “I would do it a thousand times over again.”

The cost for Mr. Weinstein for Mr. Cheeks’s one-song performance: around $10,000.

Mr. Friedman divides headliners into two categories: slow background music for a ceremony, dinner or first dance, and upbeat party tunes for a reception or after-party. He has coordinated a range of acts: John Mayer to perform “Daughters” for a father-daughter dance; Lady Gaga to sing jazz renditions of her hits during dinner; and Pitbull to kick off late-night, high-energy dancing.

He recommended that couples not only think about their favorite musicians, but also consider what would fit the crowd and the destination. He suggested Shaggy for island weddings and Mr. Bocelli for weddings in Italy. If couples want a dance party, he recommends Ne-Yo or Flo Rida, who both have cross-generational hits. For couples with smaller budgets, he might consider hiring a tenor from the Los Angeles Opera or a Broadway star — just not Idina Menzel, he said. (The range for so-called megastars is $150,000 to $250,000.)

Keeping the crowd top of mind, Eddie Kay, 41, who works in computer engineering, and Alex Zhou, 32, who recently earned her Ph.D. in economics, hired the singer Katherine Ho to perform in English and Mandarin for their wedding in Saratoga, Calif., in April. Ms. Ho is known for her Mandarin cover of Coldplay’s “Yellow” in the film “Crazy Rich Asians,” and Mr. Kay felt that the performance would be welcomed by their Chinese family members in attendance, many of whom didn’t speak English.

Evan Ross Katz, 35, a writer and podcaster, and Billy Jacobson, 30, an engineer, wanted someone “iconic” for their May nuptials in New York. So the couple booked Mandy Moore, who performed her love song from 2000, “I Wanna Be With You,” as well as her top hit, “Candy,” as guests took to the dance floor.

When hiring a music star, couples need to factor in expenses like travel, accommodations, meals, production equipment and even green room requests, which can add to the overall cost, said Jordan Kahn, who owns a namesake music company in Dallas. A headliner’s tour schedule, the wedding location and the number of songs performed can all increase the price as well, he said. It’s also rarely just the headliner whom couples have to consider: They may need to cover the costs for security teams, managers, assistants and other members of the entourage.

A cottage industry has emerged as vendors seek to help couples navigate the process. Music companies that supply D.J.s and wedding bands, like Mr. Kahn’s company and Élan Artists, often serve as the liaisons between talent managers and couples to secure talent and produce the final show.

Rachel Dalton, the president of a namesake production company in New York, helps couples negotiate and finalize contracts with talent using her background as an entertainment lawyer. Her team also personally escorts the performer to and from the venue and ensures that every technical requirement is met. Her production firm has worked with such names as Chris Stapleton, Alicia Keys and the Rolling Stones.

“Everything must be in the artist’s agreement so the couple is protected,” Ms. Dalton said. “It’s a real investment and must be treated as such.”

When David Levy, 29, the royalties manager for a music company, booked Derek Sanders of Mayday Parade to perform three songs during his wedding in Brooklyn in May with Megan Carty, 29, a pharmacist, he also hired a sound engineer and a D.J. to meet equipment needs and make sure that the day-of logistics ran smoothly.

Mr. Sanders sang “Miserable at Best,” one of Ms. Carty’s favorite songs, for the couple’s first dance, followed by two other hits, “I Swear This Time I Mean It” and “Your Song.”

“Derek didn’t just sing and leave — he hung around and took photos with our guests,” Mr. Levy said. “He signed our guest book. He had conversations with us. He was so kind.”

Many musicians enjoy performing at weddings and will often include a meet-and-greet with guests as part of the performance package.

“This is not a corporate event for a faceless company, nor is it a concert,” said Jay Siegan, who books 200 weddings a year with headliners like Celine Dion, the Killers and the Wu-Tang Clan, through his company, Jay Siegan Presents, based in Santa Barbara, Calif.

“This is the singular most important event of someone’s life,” he said.