Where the blues became rock

Oh man, looking forward to seeing this.

Much of the film is pervaded by a similar “sense of loss for a time and a place,” as Mr. Siegel put it. With the exception of the guitarist Buddy Guy and the drummer Sam Lay, who appears in a poignant scene at Muddy Waters’s house, where Mr. Lay and other members of the Waters group rehearsed, the musicians who originated the electrified Chicago blues style are gone. An interview in the film with the guitarist Hubert Sumlin, a breathing tube in his nose, is the last he gave before he died in 2011.

Even the “white boys” are themselves now in their 70s, and the clubs in which they were tutored — juke joints with names like Pepper’s Lounge, Theresa’s, Silvio’s, the Blue Flame, Curly’s and the Checkerboard — are now just memories. In one scene, the harmonica player Charlie Musselwhite stands at the empty lot that used to be Rose & Kelly’s Blue Lounge and talks about learning licks from Big Walter Horton out in the alleyway between sets.

In the film, Mr. Siegel tells of accompanying Howlin’ Wolf for a two-week engagement in Greenwich Village. Every morning, he recalls, “the Wolf,” who stood 6 foot 6 and onstage projected a gruff, even fearsome, persona, would gently knock on his hotel room door and the two would wander the streets of New York for hours at a time, talking.

“It was wonderful, but I didn’t really know how wonderful it was back then,” Mr. Siegel said in a telephone interview from his home in Chicago. “I was essentially a teenager, just riding that wave, ‘Wow, this is cool.’ ”