With the dual success of the Dead Weather and the Kills, listening to Allison Mosshart's other band, Discount, almost feels weird. It's hardly fair to judge a musician by the things he/she wrote in his/her early 20s, but Mosshart has thoroughly changed herself in the years since Discount's 2000 dissolution. Her voice is now husky from too many cigarettes; she sings about the blues and carnal desire.

You'd never know she was in a pop-punk band.

And yet, Discount existed. The Florida pop-punk quartet dropped three records, and each one is a masterwork. Sometimes called "the female Jawbreaker," Discount had a brief run, but their output still holds a lot of power. The group's first two records, Ataxia's Alright Tonight and Half Fiction, are of a piece. Their songs are anthemic, snotty slabs of emo masquerading as pop-punk. They're fun records for sure, but they pack a lot of emotional resonance if you let them. The group's swansong, Crash Diagnostic, however, is a totally different record.

Crash Diagnostic is not a pop-punk record. It's decidedly more emo for its time period, although nowadays it could be placed more in the indie rock realm, recalling Sleater-Kinney and early Pretty Girls Make Graves. The guitars are a little more dissonant. The songs don't always make obvious pop moves. These tunes are angular, spastic. Crash Diagnostic veers violently from the lumbering, dreamy "Behind Curtain #" to the punk rocker "T.V. Kiss" simply because it can. While a handful of tunes share some genes with old Discount, like "Broken to Blue" or "Medical," the album is given to these deviations. One minute it's an ethereal drifter, the next it's cranked to full volume.

These changes make Crash Diagnostic perhaps the most challenging Discount album, and therefore the last one prospective fans should pursue. Ataxia and Half Fiction are crowd pleasers. They deal with relationships with big pop-punk hooks. Crash Diagnostic is something else. It's louder and quieter in alternate movements. It goes towards some random surreal places. But while it might take a little more effort to crack, it's ultimately just as rewarding of a record.