Nelson was also a master of rewriting standards. In his hands, songs like "How Long Blues," "Don't Let the Sun Catch You Crying," "Sweet Mr. Cleanhead" and "Sleepy Time Down South" were totally transformed. He had no qualms about adding his own, often raunchy, lyrics, or switching up the tempo or arrangements.

Take "Cabaret," for example. In Nelson's Dirty South version of the 1966 Broadway number set in the Weimar Republic, he encourages people to "shut off your computers" and "that hot Web page" and get out into the clubs, where you can hear music and eat gumbo and fried fish and drink wine.

"Don't get pissed off by the prophet of doom," he urges. "And have him pee on your parade / put some fun back in your life oh lonesome one / zydeco the night away old lonesome one / get yourself to this French Quarter cabaret."

His rewrites totally reinvigorate the songs; you come away thinking his version was the first, and best.

"It's very common for blues acts of his generation to do standards," Wood says. "But rarely ever does anyone take a standard and add not just a line, but verses and verses of detail, and you hear 'em and think, 'Those are the best lyrics in the whole song, and that song's been around for 60 years.'"

He enhanced them so much he deserved partial songwriting credit — and he knew it, too.

"He would say, 'Isn't there something I can do to get my name on there?' remembers Querfurth. "I told him that he would have to get in touch with the guy that originally wrote it, and most of them weren't around anymore, and their executors weren't gonna let anybody put their name on anything. It's a tough deal, 'cause he wrote some great new lyrics for some of those songs."

Nelson was among the most urbane of bluesmen, a suave and sophisticated cat in the tradition founded by Leroy Carr that extended through Jimmie Rushing, T-Bone Walker and Cleanhead Vinson. In his youth, and as attested to by the singles collected on Cry Hard Luck, he rocked and rolled alongside pioneers like Roy Brown, Big Joe Turner and Wynonie Harris, but as he aged, he often favored even older styles.

And man, did he sport some amazing Depression-era hepcat lingo. At one session, guitarist Milton Hopkins hit a lick Nelson dug so much he shouted, "That's the way to get the butter from the duck, son!" Guitarist Sean Carney collected a few Jimmy-isms, such as "We're gonna give the babies away," "My vines have tender grapes," "I'll say a Chinese prayer for you" and "Watch your black language!"

Querfurth remembers another.

"'While the flava lasts,'" he recalls Nelson as fond of saying. "He would just say that off the cuff in any instance: 'While the flava lasts.'" Indeed, his business card bears the Zen-like legend "The blues is a feelin' as long as the flavor lasts."

Querfurth thinks Nelson's long hiatus from music during the late '50s and '60s fixed him permanently in an earlier time. "He never went through that period of modernizing, which was great," he says.

Or maybe Nelson was just stubborn.

"I don't know if it was actually that or if it was that you just weren't gonna change the way he thought," Querfurth says. "He was definitely a guy who did everything his own way and was not gonna be twisted and contorted by whatever was around him."

When I visited with him at his Third Ward duplex on Calumet Street almost exactly two years ago, Nelson was as much the creative dynamo as ever. His cluttered home was piled high with papers and binders full of lyrics, song fragments he tinkered with each and every day.

The day I was there, he was working on a song about a day at Pete Mayes's Double Bayou Dance Hall, making sure he had all the details in order, right down to the homemade sweet potato pies.

"I just wrote an e-mail to some of the guys that played with us on those albums, and I told them I felt like there were probably albums and albums worth of stuff that he never got to do," Querfurth says.

And it could be that Nelson wouldn't have had it any other way. Years ago, he shared his philosophy with an interviewer like this: "You got to know when to walk off. You've got to leave them wanting more."