When the young, woodshedded strains of folk music began to intermingle with contemporary gloss -- that is, this time around, during the 21st century boom and not the '60s "pick up yer tent, McGuinn" genesis -- the pop public's flirtation with folk instrumentation and melody ended up not being the passing fad so many expected. Who would have thought that so many Mumfords, Avetts, and Ivers would have surged out of the petri dish?

The Lumineers, who have been sawing at their instruments for a decade now, have only recently have begun getting their shine -- thanks to 'Hey Ho,' a single that's finding itself on television more and more and even threatening to poke its finger through the Billboard Top 50.

Amidst plowing such momentum, the Colorado trio has released a new song, 'Stubborn Love,' a syrup-thick love battle march that presses all the right nu-folk joy buzzers: war drums, wide swaths of cello, the Pixies-style loud-soft-loud dynamism that's engrained in our musical DNA (it's the pop equivalent of MTV's influence on movie and TV editing, after all), sidewalk-busking showmanship, and a certain brash emotional nudity and mud-caked optimism that's not just de rigeur, but dang near a prerequisite.

The song is also a multipurpose icepick of melody: It could drill itself right into television climaxes, car commercials, the VH1 (or CMT, for that matter) music video countdown, or, heck, right into the heart of the next mixtape for your summer fling.

Listen to the Lumineers, 'Stubborn Love'