The relationship between drone and noise can be hard to define. Sometimes they are sides of the same coin; other times they conflict like boxers in a clinch. It's easy to say that not all drones are noisy, and not all noise is drone. But when a band combines the best of both, making something bigger than either could muster alone, words tends to fall short.

At least, it's tough to capture the power of At All Ends, the umpteenth release from Portland's Yellow Swans. Since 2001, the duo of Pete Swanson and Gabriel Mindel Saloman have used vocals, guitar, and a wide array of effects to make music that constantly resists definition. They can sound abrasive, industrial, dreamy, electronic, even symphonic. Though they've earned a spot among the cream of the American noise underground, their music is so versatile and malleable, it's tough for any genre to fully claim it.

Which means Yellow Swans haven't always made drones, nor have they always made noise. But they are certainly great at making each, and At All Ends shows they are even better at making both at once. This is an unashamedly epic album of grand noise-drones, with ambitious pieces in search of infinite expansion. Terms like "end," "stretch," and "mass" pop up in the song titles, suggesting that for Swanson and Saloman, universes of sound can fit into 10-minute chunks of music.

If that's what they believe, At All Ends offers a convincing case. The album opens with the title track, a 12-minute journey to the center of guitar drone. Building into a holy mountain of static, it should be example number one in some future Wikipedia entry for "noise-drone." "Stretch the Sands" follows with long, screeching tones, like a horror-movie negative of the opening track's soothing waves. Those are two daunting pieces to start a record with, but At All Ends continues to rise, peaking with the masterfully-constructed "Mass Mirage". Here, Yellow Swans turn four shimmering guitar chords into first a sonic cathedral, then a trembling earthquake, and finally a pensive denouement, as the original four chords return like a phoenix escaping quicksand.

This all might sound a bit lofty, but Yellow Swans' music is far from pretentious. It's actually pretty visceral, often as fun as a rollercoaster. And they can tell a joke, too: The title of the closing track, "Endlessly Making an End of Things", must be a self-deprecating reference to the band's sonic tail-chasing. But even if they acknowledge their ambitions, Yellow Swans don't apologize for them, and they shouldn't. At All Ends is as huge as it wants to be, maybe even more.