Despite the unevenness of his records-they have ranged from brilliant to bloated-Elvis Costello will go down as one of pop music’s greatest songwriters. His missteps have come, oddly enough, when he’s teamed himself with other artists. Some of these collaborations have been-how to put this?-less than exciting. This is why I approached his latest project with trepidation. What a pleasant surprise it is, then: The River in Reverse is, for me anyway, his juiciest set of tunes and most satisfying record since 1989’s Spike. Maybe this reflects my bias toward his bluesier work-the Dirty Dozen Brass Band appeared on some of the songs on Spike, and T Bone Burnett coproduced it-but I prefer to think that the New Orleans sound brings out the best in ol’ Declan MacManus. His foil this time is the esteemed Crescent City songwriter and pianist Allen Toussaint, whose pen shows up on 12 of the 13 tunes-some of them from his own catalog, the rest new ones cowritten with Costello. (Only the title track was written by Elvis alone.) The leaders are backed by two bands-Costello’s regular group, The Imposters, and the Crescent City Horns-and guitarist Anthony Brown. Costello’s distinctive voice and songcraft make this set inarguably his, but it is also clearly New Orleans’. It’s easy to read the album as a statement about a city besieged by both a hurricane and government’s response to it. Toussaint’s own “Tears, Tears and More Tears” and “Who’s Gonna Help Brother Get Further?”-a disc highlight, by the way, with lead vocals by Toussaint and killer work by trombonist Sam Williams-take on new meaning in 2006. “Broken Promise Land,” a new tune written by both men, is aimed directly at those who haven’t insisted that Louisiana get fixed quicker-and that would be all of us.