For a trendy restaurant on a Saturday night, the soundtrack at Cadence was a familiar one: Waitstaff deftly flitted about the Mid-Market dining room amid a humming chorus of diner chatter, silverware scraping ceramic, the pop of Champagne corks and clinking glasses. But perhaps the most poignant element of the symphony was the silent, underlying ticktock of a clock counting down the restaurant’s final hours.

On July 2, owner Jay Bordeleau closed Cadence after six months in business, a stunningly short life for a restaurant expected to be a blockbuster. Its finale came a week after another closure several blocks away, that of Oro in Mint Plaza, which lasted just nine months. The two high-profile closures have put a spotlight on upscale restaurants that have sprouted in Mid-Market in the last several years, prompting the question of whether the neighborhood’s culinary boom will turn to bust.

It’s been more than four years since Twitter moved into the former Furniture Mart building — now dubbed Market Square — between Ninth and 10th streets, heralding a supposed Mid-Market renaissance. Twitter was soon joined by a slew of others, including Dolby, Uber and Square, along with multiple apartment complexes. Adding to the wave of redevelopment — and a seemingly natural fit for food-loving San Francisco — was a host of new food businesses lured by the promise of an emerging neighborhood.

The numbers reinforce the explosion. According to city data, the Mid-Market corridor — measured from Fifth Street to Van Ness Avenue — is one of the fastest-growing in San Francisco; restaurant and hotel sales tax revenue has gone from $262,044 in 2010 to $669,432 in 2015, a 255 percent increase. Among San Francisco neighborhoods, it’s eclipsed only by Divisadero (259 percent) and Hayes Valley (266 percent).

Yet restaurants have closed; other newcomers are struggling to find profitability. And for many, adaptation and creativity have proven necessary to attract diners.

“This immediate neighborhood definitely feels saturated,” said Matt Semmelhack, who has opened three restaurants in the area over the last five years, including 11-month-old Bon Marche Brasserie in Market Square. “Market saturation leads to closure or culling. And it’s happening.”

For many restaurateurs, the draws to Mid-Market were myriad, from the financial (more affordable leases, tax breaks) to the sheer space available for more grandiose projects.

“It seemed underserved by restaurants,” said Karen Leibowitz, partner at the Perennial, which opened in January. “We were attracted to the idea that we would be in the ground floor of an apartment building, and people upstairs would be interested in using us as a second kitchen. (We’ve) been surprised at how few apartment dwellers have been here.”

A lively restaurant culture hasn’t easily materialized, in part because the area is still very much dominated by office workers, which means that it dies down in the early evening and on weekends.

Other neighborhoods full of ambitious restaurants, like Hayes Valley or the Mission, attract crowds at all hours, but in Mid-Market, by 8 or 9 p.m., “everything tends to wind down in the area,” said Michael Rodriguez, owner and operator of Cadillac Bar & Grill, opened in August 2015. “The area is very much still a business district.”

And unlike the Financial District, which also ebbs and flows with business hours, Mid-Market workers don’t usually leave their offices for lunch. Though the tech companies’ free and catered meals were widely known to incoming businesses, the new restaurateurs still say that they overestimated the market.

“A lot of people, us included, missed our projections regarding how much foot traffic these offices would bring,” Semmelhack said. “Our likely clientele are staying in their offices and getting really high-quality food that’s free.” Cadence’s Bordeleau put it more bluntly: “Competing against free is really hard.”

Restaurants have been forced to adapt. To entice people out of their offices, the Perennial launched an event series — a sour beer night, for example — and in keeping with the restaurant’s ecological mantra, they’re also doing a series of monthly talks about food and the environment.

“We’re trying to make ourselves a destination-worthy bar and restaurant, so that even if you’re getting a free happy hour, that there’s something worth getting at our bar you can’t get at the office,” Leibowitz said.

Ryan Cole of weeks-old Corridor sees more potential in different audiences.

“I’m not banking on people from Twitter and Square to support the restaurant,” Cole said. “They have too many free options. They’re not the ones going out every day. The people we’re seeing are city employees, people going to the courthouse, the opera, Bill Graham (Civic Auditorium).”

Accordingly, Corridor is a counter-service spot, aimed at diners looking for a quick lunch or a dinner before a performance.

“I don’t think Mid-Market is saturated with the right types of places. And I think that’s the hard part,” Cole said. “I don’t know how many more full-service, fine-dining places the neighborhood can tolerate. But if you had more restaurants with lower price points, they’d be busy all the time.”

Case in point: When Jeannie Kim opened Sam’s Diner near the corner of Market and Eighth in 2006, street life died down after 3 p.m., so she opted to court locals with affordable breakfast and lunch, expanding to dinner years later. Nothing on the menu is over $20. On a recent weeknight, about an hour before the curtain rose for “Beauty and the Beast,” the line was out the door.

Kim is now opening a second project in the area, partnering with chef Bruce Paton to open a beer-focused project called Fermentation Lab.

The beer theme speaks to the businesses that have had more success in the area: bars. At the busy places, like Alta CA and Beer Hall, drinking is a big draw, and not just in Mid-Market, but the city as a whole right now, said Cadence’s Bordeleau. It’s why he opted to keep his adjacent cocktail bar, Mr. Tipple’s, open, while closing the more upscale Cadence, which offered a $55 tasting menu and $28 entrees.

“As the neighborhood continues to take shape, small businesses and the city alike are learning and adapting, but there is no doubt that the neighborhood’s future is bright,” said Joaquin Torres, deputy director of the Office of Economic and Workforce Development.

The Cadillac’s Rodriguez is no stranger to neighborhoods that are still developing retail momentum. He was a partner in the original incarnation of the Cadillac, open from 1982 to 1999 near the corner of Howard and Fourth — long before that neighborhood was popular.

“We were pioneers in that area,” said Rodriguez, drawing the parallel to Mid-Market’s current state. “South of Market didn’t happen overnight. It took a couple of years before it started taking off. I think we could be the next Hayes Valley.”

Whether the Mid-Market newcomers can last remains the question, lest they go the route of Cadence and Oro.

“It’s coming, we all feel it,” Rodriguez said. “If we can just hang on a couple of years, we can reap the benefit.”

Sarah Fritsche is a San Francisco Chronicle staff writer. Email: sfritsche@sfchronicle.com Jonathan Kauffman contributed reporting to this story.