James Blood Ulmer has always been a critic’s dream: an avant-garde guitarist who is also an authentic blues man. He’s scorched a whole lot of strings in his time, and howled out so many imprecations against the Man that on uptempo numbers his voice pretty much doesn’t exist anymore.

I have enjoyed just about all of the recent records he’s made with his Memphis Blood Blues Band and producer Vernon Reid (remember when Living Colour was the newest thing around?), and this is no exception. The band is tight, Blood’s voice is a ruined cathedral, and the songs here are angry, funny, sharp-edged, and wise. Bad Blood in the City contains the entire history of the blues, all wrapped up with a stylish apocalptic bow.

Sadly, though, it’s pretty clear at this point that this project is reaching the point of diminishing return. One would think that the album would gain a lot from its ostensible concept, the ravishing of New Orleans by both Hurricane Katrina and the United States government. It was recorded at the legendary Piety Street Studios in New Orleans.  But the opener, “Survivors of the Hurricane”, just doesn’t get it done, despite the gospel touches; by the time it limps to its AAA-friendly “smooth-rockin’” chorus, it has become a big thumpy thing, both conceptually and musically. Another song, “Katrina”, is more ominous and interesting, but Blood’s anguished “Tell the president! Tell the president!” at the end is just a couple years late—by now, even George W. Bush has heard of Hurricane Katrina.

Strangely, the non-concept tracks are livelier. “Let’s Talk About Jesus” is some pretty impressive neo-gospel blues stuff, even though it’s hardly as revolutionary as Blood probably thinks it is; everywhere I turn, everybody and his damn cousin are constantly talking about Jesus, at top volume. Also ace are his covers of Howlin’ Wolf’s “Commit a Crime”, Junior Kimbrough’s “Sad Days, Lonely Nights” (great one-chord/one-riff boogie there), and Willie Dixon’s “Dead Presidents”. (I’m not as sold on his slow countrified version of Bessie Smith’s “Backwater Blues”, though.)

So while I enjoy this record just fine, I don’t think it’s as strong as Birthright or Memphis Blood, and I’m not at all sure I can make any predictions about how the next installment is going to be. Maybe it’s time to shake up the band a bit, or for Reid to stop being so guiding-hands-ish, or something. Blood cannot be contained or directed; Blood must flow.

• Multiple songs MySpace