“If I check the irony/Would everybody cheer me?” Steven Page, singer-guitarist for alt-pop smart-asses Barenaked Ladies, wonders on “Testing 123,” a cheeky, self-referential jangle-pop jaunt from their sixth album. Despite the question, the album shows that BNL aren’t quite ready to play it straight. For every earnest, country-inflected love song (“For You”), there’s a nonsensical synth-pop ode to shopping (“Shopping”). For every time singer-guitarist Ed Robertson injects gravitas into a solemn, swaying song about suicide (“War on Drugs”), Page yammers a mile-a-minute rhyme about postcards of chimpanzees (“Another Postcard [Chimps]”) in the mold of their car-commerical hit “One Week.” They do loosen up the folk-pop shackles, laying strings across four tracks and working up an odd tango/klezmer groove on “Upside Down.” But the record feels uneven, as the oscillation between frivolous and serious makes both less convincing.