“The Sharpest Thorn” reunites Elvis with pianist/producer/songwriter/New Orleans legend/architect of American music, the great Allen Toussaint.

Welcome back to the Elvis Costello Song Of The Week®, our ongoing attempt to drive you ever-deeper into the catalog of the musician who most embodies the Trunkworthy mission.

The week’s pick: “The Sharpest Thorn” from The River in Reverse (2006)

Gary Stewart: “Although we know we must repent, we hit the scene and look for sins that haven’t even been invented.”

The line that climaxes the chorus of “The Sharpest Thorn” lays out the struggle between fanaticism and true faith in a falsely pious world, where the easy path of judging others often replaces the hard work needed for self-examination and action.

The song comes from—and basically serves as a mission statement for—The River in Reverse, Costello’s collaboration with the embodiment of the New Orleans music scene, songwriter/producer/arranger Allen Toussaint. The album’s varied tracks encompass many themes—an angry cry over the neglect New Orleans suffered after Katrina, a plea for the healing and restoration of a spiritual and cultural center that was wounded within inches of its life, and a tribute to Elvis’ collaborator here, who is one of his greatest inspirations and influences. “The Sharpest Thorn” embodies all three, balancing the secular and the sacred in a gospel-inspired number that even an atheist would appreciate (and draw meaning from).

Those who accuse Costello of hiding behind cleverness, snark, and wordplay can find nothing to make their case with this song’s lyrics, which honestly and movingly portray grace, struggle, and salvation. When his vocal goes from the lament of the verses to the intense, soaring plea of the choruses, the music follows, and so do you. You just can’t help feeling challenged, troubled, and, ultimately, inspired—like a believer.

David Gorman: I know we’re here to talk about Elvis, but here’s the thing about Allen Toussaint: I’ve bought almost every album he’s produced (most of which he also wrote all or some of), and I’ve only found one that isn’t great. Many of them are among the best records ever cut, like Rejuvenation by The Meters, Right Place Wrong Time by Dr. John, not to mention a couple of the albums Toussaint put out on his own. Then there are the songs he wrote, which have been covered by everyone from The Doors to Devo, Glen Campbell to Phish. Elton John compared him to the Dalai Lama. The President gave him the National Medal of Arts. We talked a few weeks ago about what a big deal it was when Elvis collaborated with Paul McCartney (on “That Day Is Done”), but make no mistake, Elvis collaborating with Toussaint is just as heavy.

They worked together on another Elvis Costello Song of the Week, “Deep Dark Truthful Mirror,” but Toussaint was just a guest musician on that one. On “The Sharpest Thorn,” he’s a cowriter and full musical collaborator. Melodically, lyrically and musically, everything just works and it all just soars. I love everything about this song, beginning to end—from Toussaint’s elegant church-funk piano that kicks off the song to the crazy Dixieland breakdown that ends it. And, of course, the lyrics, which capture the sacred profanity of New Orleans in a rare, subtle way. There’s strut, swagger, sin and salvation all on parade, and, in the last verse, a humble clarity that comes out in a verse that twists everything that came before—even the song’s title—into something as human as a hangover. While the whole River in Reverse album has songs that are more political and more sentimental  (including some of Toussaint’s older songs delivered with renewed ferocity in the wake of Katrina), this song is where both of their talents blend seamlessly into something that sounds like it’s been around forever.

 …and while we’re on the subject: The HBO series Treme wove Costello and Toussaint’s collaboration into the plot of the show, with both men recreating their collaboration on camera. Costello appears in the first two episodes of the series, attending a Kermit Ruffins show in the premiere and appearing in the studio with Toussaint in episode two.

Catch up on previous Elvis Costello Songs Of The Week with our ever-expanding playlist: