The Wales-based band Los Campesinos! isn't actually Welsh, as a savvy observer might glean from their English lyrics, Spanish handle and band members' names, like "Neil." That polycultural jumble is mirrored in their durable, malleable indie rock, which seems just as capricious in its loyalties, always flitting between heart-sleeved pop-punk and spring-wound post-punk, romantic earnestness and vitriol. Their turn-on-a-dime, shout-sung, TMI tantrums evoke a Jim Hinson version of Art Brut, but with more glockenspiel and more emphasis on soul-baring than arch humor. It's irritatingly irresistible. The equally jittery British indie rock band Johnny Foreigner opens. —Brian Howe