No matter how exhilarating the pendulum-swinging dynamics of post-hardcore music can be, they're also pretty tough on soft ears. While Q and Not U, Thursday, May 3, at Double Entendre Records, will never be confused with puffsters like Blink 182, the band makes more concessions to the cochlea than do many of the acts that come from its Washington, D.C., hometown. Though the band works a pair of fast-action guitars as nagging and scratchy as anything ever mustered by Fugazi, there are ghosts of melody buried in the gristle. On Kill, No Beep Beep (Dischord), guitarists Chris Richards and Harris Klahr mate avant-garde lyrics with the get-up-and-dance gusto of born soulsters and the guttural passion of the angriest punks. Listeners are left to choose between boogying and slam dancing. Yet despite its sunnier elements, this is definitely not pop music. Q and Not U dishes out the debilitating confusion and requisite postmodern isolation as deftly as any other post-hardcore/emo unit. Andi Camp, Ted Leo and the Pharmacists and Sacco & Vanzetti fill out Thursday's all-ages bill.