Credit: Brian Stowell

If you’ve had a late-night doobie-smoking session recently, chances are Ray LaMontagne has served as the soundtrack.

For more than a decade, the songwriter has crafted gorgeous folk rock that splits the difference between CSNY’s Laurel Canyon vibe and the quiet introspection of Nick Drake. But with his latest, produced by My Morning ­Jacket’s Jim James, he’s beefed up his sound for his loosest, most blissed-out set yet.

The title, Ouroboros, refers to the mythological symbol of a snake eating its own tail, and that’s exactly what LaMontagne’s created here: All eight tracks daisy-chain seamlessly. There are distinct moments: “Hey, No Pressure,” with its fuzzy Led Zep-style guitars, is as groovy as it sounds; “A Murmuration of Starlings” veers into a Dark Side of the Moon-ish space odyssey.

Even with such sonic experimentation, ­LaMontagne’s hushed, nicotine-­stained voice doesn’t get lost. “You’re never gonna hear this song on the radio,” he sighs on one track. And he’s right: Ouroboros is a perfect throwback to the lost art of the album-length format.