CHICAGO —

ancing Aloud,” a sign said. Onstage, guitarist Corey Dennison, 43, white and well tattooed, had just opened an instrumental conversation with a grandfatherly figure in a White Sox cap.

“This is my old man, Mr. Carl Weathersby,” Dennison told the crowd. “He taught me everything I know about the blues.”

Weathersby, 65 and African-American, nodded. The notes rose, fell and tangled like family voices around a dinner table. The players, related only by a passion for music, grinned and winced the way soloists do.

In the audience, 100 blues lovers roared, clapped, drank and chattered in three or four languages.

This was Kingston Mines, the oldest, biggest club of its kind in Chicago. Like the rest of the international audience, I was here to listen to an embattled American sound — Chicago-style electric blues, born in the mid-20th century as African-American families moved north from the Mississippi Delta.

In that migration, legions of country blues musicians traded their acoustic guitars for electrics, started playing their harmonicas through microphones and launched an era of rough-edged, streetwise music, sibling to soul, cousin to gospel.

The sound filled mostly black clubs on Chicago’s South and West sides. New arrivals played for tips on Maxwell Street, and the biggest names released albums on Chess Records and blazed a musical path that rock ’n’ roll soon would follow.

But Chicago and pop culture have moved on. Though the vast, free Chicago Blues Festival takes over Millennium Park every June, and the locally headquartered Delmark and Alligator labels release new blues and roots tunes, rap music now dominates the South and West sides.

You must go to the Loop and north, where the tourists are, to find the remaining handful of all-blues clubs.

I wanted to see and hear them before things changed any more, so I spent three days and nights this summer chasing Chicago blues through five clubs, one museum exhibition and one storied old studio.

Kingston Mines, born in the late 1960s and a fixture on Halsted Street in Lincoln Park since 1982, was my first stop. It features two stages (so two bands can alternate sets without long delays in between) and a kitchen (Doc’s Rib Joint). The live music plays until about 3:45 a.m. every night except Saturday into Sunday, when it lasts an hour longer.

As I chatted with the musicians between sets, I learned how Weathersby broke in as a guitarist for bluesmen Albert King and Billy Branch, started his own group, then hired Dennison and mentored him for years. Nowadays Dennison and his band play two nights a week at Kingston Mines. Weathersby, who has moved out of state, had dropped by to listen.

At the Chicago History Museum, I browsed through the “Amplified: Chicago Blues” exhibition (through Aug. 10, 2019), which includes vintage photos of wild nights in long-gone South Side clubs; hands-on features inviting you to sing or play guitar; and an introduction to many of the region’s key players.

From Mississippi came Muddy Waters to sing “Mannish Boy,” Howlin’ Wolf to sing “Smokestack Lightnin’,” Bo Diddley to lay down the five-beat syncopated rhythm that drives “Who Do You Love?” and Willie Dixon to write “Hoochie Coochie Man” and shape the Chicago blues scene for years as a bassist and producer. From Louisiana came harmonica player Little Walter and guitarist Buddy Guy, now 82 and still performing at his club, Buddy Guy’s Legends.

My other daytime stop was Willie Dixon’s Blues Heaven Foundation, a surprisingly compact building that housed Chess Records from the mid-1950s to the mid-1960s. There, tour guide Janine Judge led me upstairs to the studio where Waters, Diddley and Dixon did some of their best work. This was also where Chuck Berry recorded “Johnny B. Goode” in 1958 and Etta James recorded “At Last” in 1960.

Judge, carrying a portable speaker, cranked up the volume on classic songs and pointed out the late Dixon’s old bass in one corner. She explained how brothers Leonard and Phil Chess built the label and how Dixon sued Led Zeppelin decades ago, accusing the band of using his words and music in the songs “Bring It on Home” and “Whole Lotta Love.” This led to settlement payments, amount undisclosed.

Without that cash, who knows whether this building would still be standing?

By night I club-hopped, paying cover charges of $5 to $12.

At B.L.U.E.S. on Halsted, down the street from Kingston Mines, I stepped in just as host Big Ray was asking the out-of-towners where they were from (England, Hungary, Australia). The club, snug and narrow, holds about 60 people. The stage was so small that the bass player sat on the keyboard of an upright piano.

Many a music lover has spent an evening wandering back and forth between B.L.U.E.S. and Kingston Mines.

At Rosa’s Lounge the scene is similarly intimate, and the hospitality has a homespun Italian inflection. Italian immigrant (and drummer) Tony Mangiullo opened the place in 1984, and it’s been a fixture in the Logan Square neighborhood.

Onstage, Nigel Mack, a singer and multi-instrumentalist, was working without his usual guitarist. That meant we didn’t get the harmonica heroics Mack is known for, but I was happy to sit up close and admire his slide guitar work.

The city’s blues scene “goes up and it goes down,” Mack told me during a break. “But the state of the blues has got to be healthier here than it is anywhere else in the world.”

At Buddy Guy’s Legends, a posh place next to the Hilton in the South Loop, I caught Mz. Peachez and Her Casanovas.

If I were smarter, I’d have arrived early enough to order dinner — those who reserve ahead and sit to eat get the best spots. While I stood in back, Mz. Peachez assessed her crowd and veered from standard blues titles to disco favorites “Bad Girls” and “I Will Survive.”

At the House of Blues in the heavily touristed River North area, I was too early for live music but got a juicy burger with sweet potato fries. To those who would say that patronizing the House of Blues in Chicago is like eating at Taco Bell in Los Angeles, I can only say: Yes, it is. But it books a lot of local blues acts, often two per night.