THE WAR ON DRUGS Ironically, druggies LOVE them!

MY ROOMMATE was drawn in by the sound. "What is that you're playing?" he asked, wandering wide-eyed down the hallway.

"The War on Drugs," I said. "Weird songs, huh? They don't really change. They just sort of shift on up and cruise on ahead. They're from Philadelphia. Came up with Kurt Vile."

"Dude!" my roommate said. "I was gonna say Kurt Vile. When you first put it on, I thought it might be his new album." My initial reckoning was similar. It was only upon multiple listens that I unearthed the singular, hazy beauty that is the War on Drugs.

When I first heard the recently released Slave Ambient, I had to remind myself: The War on Drugs' auteur, Adam Granduciel, played in Vile's band, and vice versa. They've recorded together, even shared a studio and engineer. "We're both super dedicated to music," says Granduciel. "For a year we were doing it four or five nights a week, recording all the time, jamming, and playing." Granduciel and Vile developed an intense connection, collaborating on recording each other's songs.

"It was just a pretty inspired time," Granduciel adds. "You just learn a lot when you experiment all the time. I lived in a big house, so we had the space to experiment with really whatever we wanted to." It was there, in the later half of the '00s, that they developed the voices—concentric circles and all—that kicked off their careers.

But for as much as Granduciel shares with Vile—the raspy delivery, throwback love of tape machines, and smoke-filled, sunburned psychedelia—Tom Petty also seems an equally relevant touchstone. Granduciel's delivery reflects and mangles Petty just like Petty did with Bob Dylan. Each step removed, the nasal drawl becomes cooler, a little more laidback, a little more stoned.

Slave Ambient is an album about feel. Songs are simply structured—rarely shifting, dynamic straight lines layered with scores of twinkling melodic instrumentation. The track sequence is important. Drone-y and atmospheric passages link the songs, and provide counterpoint and respite to the songs' sturdy march. Like a car pulling back on the interstate from a dreamland of segues, the proper songs hit cruising speed in a matter of seconds.

As for singing, repetition only goes partway. While he often picks a single melody to circle around and wrestle with, Granduciel does not repeat his words. There aren't really choruses or rhymes. It's all about how the words sound. Imagine taking a Petty hook, isolating it, and repeating it. As it revolves, Granduciel pulls and pries at the structure with hazy, poetic uttering, a wash of disparate, surreal, and literary phrases—Dylanesque in the way they go and go and go.

During a patchwork writing and recording process in 2010, Vile visited the studio and ended up playing guitar on two tracks ("Best Night" and "It's Your Destiny"). One thing the friends do not share, however, is Vile's propensity to plumb darker corners of the soul, at least in sound. Despite the title, Slave Ambient is welcoming and soothing, dusty and moving, encapsulating strong senses of journey and time.

Until last year, both Granduciel and Vile played and toured in each other's bands. Touring demands on each became great enough to necessitate full-time lineups. The moment was bittersweet. "There's a really intense connection there," Granduciel says. "I like to think that, at least with recorded output, that we'll continue to work together."