(JessicaReaves/NYTimes.com) He worried even as he oversaw the finishing touches on the new location of his club, Buddy Guy’s Legends, which is part musical venue, part museum. He is worried that his club cannot provide enough exposure for all the musical talent that comes through Chicago, and worried that young people are not exposed to the music he has loved all his life.
 
He is worried, in short, that the city’s long, proud reign as the world’s unequivocal blues capital might be fading into memory.
 
When Mr. Guy arrived here in 1957, it was the heyday of Chess Records, Muddy Waters and Howlin’ Wolf, and there seemed to be a blues venue — like the 1815 Club, Theresa’s, the Blue Flame Lounge — on every other corner. Some were no more than tiny rooms that could fit 35 people if no one took a deep breath.
 
There were so many clubs, Mr. Guy said, “you couldn’t count them all.”
 
One reason the clubs thrived, he said, was because “back then, everybody had a job.” People could afford to go out, and everybody wanted to hear the famous Chicago blues.
 
“When the Beatles started, they came here,” Mr. Guy said. “When the Rolling Stones started, they were on 21st and Michigan, trying to find Chess Records.”
 
Those days are long gone. The relocated Legends, which opened its doors on May 28 at 700 South Wabash Avenue, is one of the city’s few remaining venues dedicated to live blues. Mr. Guy hopes his club will provide emerging blues musicians with the kind of exposure he got playing at the 708 Club and the Blue Flame.
 
“If there wasn’t a club when I came here, nobody was going to see me walking down 47th Street and say: ‘There goes Buddy Guy. One day he’s going to be a guitar player,’ ” said Mr. Guy, an energetic 74. “I had to go into those clubs and play.”
 
Lincoln T. Beauchamp, known as Chicago Beau, is a musician, magazine publisher and author of a book about the city’s blues history. The blues community that once flourished on the South and West Sides, Mr. Beauchamp said, fell victim to changing social and economic conditions.
 
“Pre-integration, the black community was a lot more vibrant,” he said. “Along 47th Street and Cottage Grove, you had a community that was able to sustain itself, and the blues and jazz clubs were part of it, not just socially but also politically.”
 
“Now, as gentrification takes place and the neighborhoods crumble,” Mr. Beauchamp said, the social fabric changes and the clubs disappear. “You’ll probably never again see the same kind of deep, soulful pulse coming from the neighborhoods, because the neighborhoods aren’t there anymore.”
 
For the most part, Mr. Beauchamp said, younger black musicians are not drawn to the blues. “They’re not completely detached from it,” he said, “because it’s part of who we are. But it’s just not what inspires them.”
 
Bruce Iglauer, president and founder of Alligator Records, a major blues and roots record label, said he had watched the blues in Chicago become a tourist attraction — sanitized, prepackaged music for “middle-aged white people who discovered it during college,” he called it.
 
Blues players and their fans are aging, Mr. Iglauer added, and they are not being replaced.
 
“Chicago radio stations don’t play the blues, so young people aren’t hearing it anywhere,” he said.
 
Although he gives the city credit for continuing to back the Chicago Blues Festival, the annual three-day series of free performances that begins Friday in Grant Park, Mr. Iglauer said the city could be doing “so much more” to support club owners.
 
The day before opening night, Mr. Guy showed off his club to Mayor Richard M. Daley, who stopped by for a tour and to pay homage to Mr. Guy.
 
“People come here and the first thing they want to do is hear the blues,” Mr. Daley said. “That’s the big selling point. They come from all over the world — heads of state, diplomats.”
 
Growing up in Louisiana, Mr. Guy was a teenager when his family got a phonograph. He then saved up and sent away for the 78 r.p.m. records of the songs he heard on the radio.
 
When he came to Chicago, Mr. Guy could play the guitar — “one or two licks” — but he had chosen the city for its promise of steady work and good pay. The music, he said, was secondary.
 
At night, however, he went to blues clubs and watched his heroes strut the small stages, lamenting lost loves and hard times. One day, he said, “they were asking me to play with them.”
 
Five decades later, he is still playing an international festival circuit that would exhaust most people half his age. But Chicago is home.
 
“When I got here, it was September,” Mr. Guy said, “and the birds were flying south, back to Louisiana and Texas and Florida. And I told the birds, ‘You’re smarter than I am.’ ”
 
Then he started working with the city’s top blues players.
 
“And now they’ve all left me here,” he said. “Someone’s got to carry on.”