Portland, Oregon's dreamy indie folk duo the Helio Sequence have built their discography on a series of somewhat unfortunate but ultimately sound-shaping external circumstances.

Starting off with a focus on ambient soundscapes and buried vocals, the band's experimentation with bringing the vocals to the forefront for its yelpy 2004 album, Love and Distance, resulted in singer Brandon Summers damaging his vocal cords shouting the songs out night after night on tour.

His bruised voice was reborn in a raspy Waits-meets-Dylan style, which informed the overarching indie folk feel of the band's 2008 breakthrough, Keep Your Eyes Ahead, and brought out its more somber, low-lit moments.

In the four years between that album and the Helio Sequence's fifth full-length, Negotiations, their practice space/studio flooded while they were on tour, wiping out some of their gear and leaving them in need of a new place to record and create.

Instead of a shared practice space, the duo found an enormous disused industrial space in an otherwise unoccupied building and set about sculpting the songs that make up Negotiations.

Their ability to stretch out in a much larger space (one without anyone else around to come into the band's mental landscape) is reflected in the patient tones and insular approach to almost every song here.

Spacious rockers like the title track and "The Measure" are defined by their open, chiming guitar lines and Summers' languid melodies.

The folk tendencies that filled Keep Your Eyes Ahead are revisited on songs like "December" and expanded on tracks like the completely improvised "Harvester of Souls." The band's experimentation with improvised lyrical forms, synth patches, and warm analog echoes was also enabled by late-night sessions in an isolated environment.

The lush synth pop of a song like "Silence on Silence" is sprinkled with spacy echoes and warm washes of keyboard bass.

The song is a prime example of how the band has deepened its sound even further, adding atmosphere to its already metered pop songs.

Negotiations' 11 tracks ebb and flow in similar ways to one another, but upon close inspection, the deft placement of nearly hidden sonic details is what makes the album so interesting, and breathes life into the band's already enjoyable soul-searching pop.