I first heard the Cave Singers in Neumo’s, a small, sweaty bar in Seattle. The in-house DJ was spinning in anticipation of a gut-busting rock ‘n’ roll powerhouse out of Detroit. As the crowd continued to grow, the DJ kept the blood flowing with some pretty meaty selections. Then, as if in one of those grand, Hollywood moments of clarity, he introduced me to the Cave Singers. I can’t be sure whether it was Pete Quirk’s raspy, earnest vocals, the gentle rhythms that build into dramatic crescendos, or the constant threat of harmonica that really seduced me. Whatever it was, I left my company and demanded to know what was coming from the speakers. And in classic DJ fashion, I was told in a slightly condescending tone that it was the Cave Singers. “They’re great”, I offered. “I know”, replied the DJ. It occurs to me now, listening to their brilliant new LP, Welcome Joy, that not only had I been introduced to a band, I’d been introduced to a place: the back porch at sunset.

Hearing Welcome Joy, the second full-length from the Seattle threesome, will quickly bring you to the back porch at sunset: a warm and intimate place that so many in the indie folk field try to find, but so few actually do. “Come on baby, let’s take a ride”, coos Quirk to open “Summer Windows”, the delicate and swift-rolling opening track. The track is essentially a four-minute ode to life on the road and finding your way through the heaps of shit that the road often entails, set atop delicate acoustic fingerpicking. The more one listens to Welcome Joy, the more it’s impossible not to feel like embracing the back porch, yet soon moving along.

“Beach House” takes listeners to a comfortable place where one’s settings don’t necessarily define themselves. Quirk remains defiant, his raspy pipes howling over a looping guitar rhythm that’ll take years to get out of your head. The first track released to fans before the release of Welcome Joy is a perfect single and as good as any “summer song” I’ve ever heard.

Yes, it sounds like it has a thousand times before. Yet the rustic charm that remains beguiling throughout Welcome Joy makes it seem as if the Cave Singers have barely lifted a finger to craft each of the ten tracks. The album doesn’t just feature prolific harmonies; the record is one massive, joyous harmony. That back porch must be one expansive, fruitful place to work.

While I’ve been quick to paint Welcome Joy as 2009’s contribution to the long-dead flowers-in-your-hair folk aesthetic, it’s not all relaxed, West Coast musings and patchouli smoke. In fact, when the Cave Singers shed their stools and acoustic guitars in favour of a rollicking, punk-leaning sound, some of the recording’s finer moments are heard. What keeps it intact, however, is how not a bit of the Cave Singers’ attention to harmony gets lost in the process.

“At The Cut”, a percussion-heavy, sweaty, and raging three-minute dust-up, sounds as if Quirk & Co. have not only shed the skin of their previous release, 2007’s rather light and airy Invitation Songs, but as if they’re scratching at the skin, eager as hell for some sort of evolution in their sound.

But for the time being, the Cave Singers ought to be proud of Welcome Joy. It’ll be classified as a folk record, simply because of its fondness for simple acoustics. Yet here’s a thought, and this might be as good a compliment as I can offer Welcome Joy. If one is travelling the road for longer than an hour, a battle between passengers for control of the iPod usually ensues. An unbalanced and grooveless road trip is usually the result, so let’s consider Welcome Joy for what it is: perhaps the best road trip record of 2009.

Swift, rising verses bring me to the back porch. Emphatic yet rarely overbearing choruses, all delivered in a subtle manner, will always bring me back to the road. The Cave Singers have mastered the art of give and take.

• Multiple songs MySpace