For aging punks, career options are limited, to be kind. They can continue to play the Warped Tour year after year or turn themselves into nostalgia acts, as the reformed Sex Pistols have done. Or, judging by the new album by safety-pin-era holdover Elvis Costello they can do something truly punk: ignore the rise of file sharing and make a record of thematically linked songs that demands listeners stick with it from beginning to end. Now that CDs can easily be dismantled with the help of an iPod's ''shuffle'' function, what's more obnoxious than reviving the concept album?
The Delivery Man doesn't have such a clear-cut theme, since this quasi-concept disc contains only half the songs Costello wrote for a planned work about an unhinged man named Abel who commits murder in a jealous rage, or something like that. Sounds like country music, and it sort of is: Recorded largely in Mississippi, the album steeps the manically prolific Costello's most recent slew of songs (the other half being more generalized rants and love songs) in sleepy honky-tonk (the lovely ''Country Darkness'') and white soul (the hopped-up ''Monkey to Man'').
American roots music still tends to trip up Costello. His country ballads have always tended toward the lugubrious, as is the case here. (Emmylou Harris' pretty but typically stillborn harmonies don't add much.) It's too bad Costello didn't stick with his original idea, since the tunes about Abel -- like the title song, the crazed ''Needle Time,'' the twisted lounge pop of ''The Name of This Thing Is Not Love'' -- are the disc's most vibrant. Driven by deranged theremins and rattled drums, they have a roughshod, barnjam quality that matches his dark murder-ballad material. The album delivers, all right, if not all the time.