For Elvis Costello, appearing on Late Night with Jimmy Fallon isn't just a means of self-promotion. It's also a networking opportunity.

How else would he have met The Roots, the impossibly hardworking Philadelphia hip hop band that's been serving as Fallon's house band since the show began in 2009?

Sharing reputations for fierce eclecticism and a promiscuous eye towards collaboration, the odd pairing first shared a groove when Costello came on the show in 2009. The songwriter appeared several more times in the subsequent years, and by 2012, on Questlove's ballsy suggestion, they'd agreed to take their relationship to the next level: by recording a full-length album.

"While I’m thinking, 'I wonder what they intend to play with me,' they were obviously plotting on locking the door once I got into the studio and not letting me out ‘till we made a record," said Costello. "Where we've headed since then is all about enjoying playing together on these occasions and realizing that we had the means to make a record and then we just needed the will and intention to make something that held together as a story."

Sharp and soulful in equal measure, matching Costello's biting storytelling with The Roots' propulsive, funk-driven grooves, the ensuing LP—Wise Up Ghost—dropped last month. In a recent interview with The Atlantic Wire, the 59-year-old songwriter opened up about its impetus, the critical reaction, and just why people seem to think this particular record is somehow more "collaborative" in nature than any other he's recorded in a four-decade career making pop records.

The first hurdle for this project: deciding when to go public with the news. 

Costello was sold on the idea "about five minutes after [Roots drummer and sometime frontman] Quest[love] suggested it," he said. "But we didn’t tell anybody else we were doing it and didn’t really put any big pressure on ourselves by saying, 'Oh, we're making an album.' We just wanted to play, exchange ideas, beginning with the idea of revisiting one of my songs, which I thought was a shrewd choice."

That theme—dropping lyrical snippets from previous Costello songs in new musical context—crops up throughout Ghost; "Stick Out Your Tongue," for instance, borrows heavily from Costello's 1983 track "Pills & Soap," while the waltzy "Tripwire" tips a hat to "Satellite."

"I think I'm pretty much correct in saying that 99 percent of the lyrics that we assembled into a new story were unknown to 99 percent of the [new album's] audience," Costello said of the decision. "More importantly, what the songs were actually saying had not been diminished by time. If you take a song like the lyrics for 'Refuse to be Saved,' which I sang first with very different music in 1990, the lyrics are kind of horribly true. If we sing it with more force now, maybe people will hear it this time."

"I've written a lot of songs," the singer added. "You don't want to be too self-satisfied that just because you wrote it, that means everybody's heard it." And anyway, he's not impressed by those savvy enough to list the sources of the lyrical content: "It reveals nothing. It reveals that you know my catalog to a perhaps unhealthy degree, 'cause I'm of the mind I don't make records for fetishists." 

The songwriter's creative process with The Roots took place primarily via email, swapping words and drum tracks instead of sharing a studio. Costello would send over a lyric, "and then Quest would come back and say, 'I got that.' A beat would arrive, and that beat would be completely different than the one I'd proposed—it would be half-time. Like, 'Oh, you're hearing it like that, then?'"

So emerged "(She Might Be a) Grenade," a tense, start-stopping fantasy of "this one woman revolving around a pole in a dead-end club out by the airport, staring into a reflection and she has a hallucination of a woman walking through a marketplace with a bomb strapped to her chest." How do you give accompaniment to such a delirious vision? "You’ve got to try and put some soul into such a wretched subject matter," Costello deadpanned. 

With Costello in charge of the record's lyrical content, Black Thought, The Roots' lead vocalist and rapper, is notably absent from proceedings, a gap that's irked some Roots fans and critics alike. "No one raps at any point," observed critic Jayson Greene in a lukewarm review for Pitchfork, "which seems like a missed opportunity to make something unusual happen." That wasn't part of the plan, Costello says ("there was no masterplan, it was all sort of in response to the material"), but simply how things naturally unraveled.

"The last thing anybody wanted to do—as Quest was quite concerned—was for people to perceive this as 'My Rap Album' or some affectation that was ill-advised," Costello explained. "Black Thought’s just too good to be a bit part player on a record. And there are other records the Roots have made in which he doesn’t appear."

Plus, the prodigious emcee will be appearing on a collection of Wise Up Ghosts remixes set to appear in November. Costello had nothing to do with its making. And he's irked by the tendency to harp on about the collaborative nature of his, err, collaboration with The Roots: "I never plan to collaborate with anybody," he insisted. "But I keep reminding people when they keep hammering on about this collaboration thing: you know, all music is inherently collaborative. The only time people make note of it is when you come from different contrasting worlds of music, and the juxtaposition somehow strikes people as curious or funny or potentially hazardous."

Not that the punk and New Wave veteran particularly cares what critics are saying.

"Even when I was a teenager, you kind of knew some of your teachers were idiots," he griped. "If one person that expressed an opinion could write one of these songs, I’d be extremely surprised. Or any of the ones that we’ve ever written."

And anyway, he's already onto the next thing, a northeastern solo tour in November.

"I’m not gonna lie awake at night worrying about it," he said.

All photos: Associated Press