Big Thief named their debut album Masterpiece. For a relatively unknown band at the time, that title set a lofty precedent. There was something almost sarcastic about it, as if the folk-rock quartet decided to present this project to the world knowing full well that it might not find big success, but naming it as one anyway. The opposite happened. In the years since Big Thief released Masterpiece, they have become enormously popular, touring at a near-constant clip. Sophomore album Capacity was critically lauded for its ability to tell small stories that spoke to a universal truth, and lead songwriter Adrianne Lenker is now widely regarded as one of the most technically skilled and lyrically incisive musicians to emerge over the past five years. Her affect is often described as “mystical,” and her songs have the predictive quality of an oracle — she can tell the story of an entire life in under five minutes.

Cycles fascinate Lenker. Her most recent solo album, 2018’s abysskiss, opens with “Terminal Paradise,” a song about energy transference or reincarnation. “See my death become a trail/ And the trail leads to a flower/ I will blossom in your sail/ Every dreamed and waking hour,” she sings. A reworked version of the song appears on Big Thief’s new album, U.F.O.F., as does abysskiss track “From.” This is Big Thief’s first album for 4AD and it’s being billed as their most collaborative to date, but the reimagining of two of Lenker’s solo tracks emphasizes how inextricably tied to her vision this band really is.

Though Lenker, guitarist Buck Meek, and bassist Max Oleartchik all attended the prestigious Berklee School Of Music, both Masterpiece and Capacity favored deceptively simple song structures over noodly, dense arrangements. U.F.O.F. maintains that sense of ease, but it is more impressionistic and more exploratory than the band’s previous work. Opening song “Contact” is slow and somber from the outset, but it descends into chaotic improvisation soon after. This album is, to put it plainly, loose and jammy at certain moments, which is the result of so much time spent on the road. Lenker is prolific, and writing on tour is as much a necessity as it is a method of self-preservation. “I’m not nervous to open up into that place,” she said of writing in front of her bandmates during in-between moments on tour. “If I couldn’t write in front of them, I’m not sure how much I would write at all, because I’m always with them.”

It’s a crisis of capitalism that in order to flourish as a musician one must endure a relentless touring schedule, but through Lenker’s gaze, there’s something unquestionably romantic about her vagabondish lifestyle. On “Century,” she captures memories in short, bright flashes while James Krivchenia’s drums pitter patter like a gentle storm: “Dogs eyes/ In the headlights on the driveway/ Cool autumn rain/ Bugs died/ On your windshield on the freeway/ Wonder if you’ll be the same.” Still, transience means saying goodbye over and over again, and there is a sadness underlying many of the songs on U.F.O.F. The title track’s melody shifts with the changing wind as Lenker bids farewell to a “UFO friend,” her words dripping out in rapid succession, like a leaky faucet. Lenker’s best songs can often read as wordy on paper, a little bit overstuffed. When she sings, though, they tumble forth as if conjured from someplace outside of the atmosphere. It’s hypnotic.

That Big Thief were inspired by New Age music while writing this album is no great surprise. The natural world, and the forces that guide it, have always been of interest to this band, and though many of their songs address anonymous women (Jodi, Betsy, Caroline, Violet, and Jenni in the case of this album) they invoke Mother Earth with unrelenting regularity. Single “Cattails” contemplates nature’s steadfast hold, the elements that remain long after someone beloved passes away. In grief, it is only human to seek out places that remind you of the person you lost, and Big Thief lean into that instinct here: “With your wrinkled hands/ And your silver hair/ Leaving here soon and you know where/ To where the cattail sways/ With the lonesome loon/ You’ll be riding that train in late June.”

Death is the only constant, and as much as Big Thief languish in the beauty of the surrounding world, fatalism grounds this album in an unsettling certainty. “Orange” is a love song arranged simply on acoustic guitar that contemplates the inevitable death of a partner. As Lenker’s sights grow darker — hound dogs howl at the stars, pigeons fall like snowflakes — she works herself up to a climactic realization: “Fragile is that I mourn her death/ As our limbs are twisting in her bedroom.” On the hazy “Open Desert,” you hear Meek’s fingers slide across the fretboard as Lenker contemplates another ending, picturing the “white light of the waiting room/ Leaking through the crack in the door.”

These are the preoccupations that keep people up at night, but Big Thief don’t wallow in angst on U.F.O.F. Moments of bliss eclipse the sorrowful. The fact that this album was recorded live off the floor gives some tracks an in-the-moment, improvised quality. “Strange” is a jaunty funhouse of a song that unwinds like a twisted nursery rhyme, as Lenker sings about seeing a luna moth cry “lime green tears/ Through the fruit bat’s eye.” As Big Thief tunnel further into this psychedelia, the accompanying arrangement starts to lose its footing; Oleartchik’s bass bubbles up from below, Lenker’s voice reverberates outward, and a synthetic sighing mist descends. Something similar happens toward the end of the arid, hallucinatory “Jenni,” when Meek suddenly breaks free to play the same sustained chord over and over again, to be eventually overtaken by Krivchenia’s thundering drums.

Big Thief get weird on U.F.O.F., to great effect. On Masterpiece and Capacity, they were making folksy rock songs that would absolutely play in a Pilates studio or at a cafe or on one of Spotify’s many “chillax” playlists. U.F.O.F. isn’t an outlier, not exactly, but it isn’t as conventional, and it’s exciting to consider the directions Big Thief might go in from here. Lenker has been putting out music since she was a teenager, and while it’s long been established that she’s a formidable songwriter, U.F.O.F. documents a band coming into their own, messing around with new ideas and having fun doing it. Listening to it feels like sharing in that experience.

U.F.O.F. is out 5/3 via 4AD.

Other albums of note out this week:

• Empath’s fun as hell Active Listening: Night On Earth.

• Qasim Naqvi’s debut album Teenages.

• Fury’s ferocious Failed Entertainment.

• L7’s first album in 20 years, Scatter The Rats

• YG’s delayed 4REAL 4REAL.

• Bad Religion’s 17th album Age Of Unreason.

• Barrie’s inviting Happy To Be Here.

• Tacocat’s Sub Pop debut This Mess Is A Place.

• Pile’s expressive Green And Gray.

• The Dream Syndicate’s J Dilla-inspired These Times.

• Versing’s spiky 10000.

• Filthy Friends’ (Peter Buck & Corinne Tucker) Emerald Valley.

• Truth Club’s earnest Not An Exit.

• An Horse’s rallying Modern Air.

• Body Type’s new EP, the aptly titled EP2.

• And finally: Vampire Weekend’s long-awaited Father Of The Bride.