When Rostam Batmanglij turned thirty, he decided to move to Los Angeles. He had arrived in New York, in 2002, to study music at Columbia University. There he befriended a group of students with whom he formed Vampire Weekend, the playfully erudite pop band that has more or less defined his adult life. Like many successful, creative people, he assumed that he would never leave New York. And, like many people who experience this success at a young age, he did. In the winter of 2013, he left for a tour with Vampire Weekend, and, while he was gone, movers packed up his things and transported them to a small house on the east side of Los Angeles. “I realized I would probably spend a lot of time in a studio for the rest of my life,” he told me. “And I wanted to do it in a studio that got natural light.”

Batmanglij thinks about time in grand terms—the arc of a career, the span of one’s life. He said that he wants to make ten solo albums before he dies, each different from the previous one. He talks at length about legacy and context, the extent to which one’s musical identity can only be defined by the past. Yet his career has been eclectic and unpredictable, characterized by a seeming lack of big-picture strategy. In Vampire Weekend, he was the keyboardist, guitarist, and backup vocalist, and he also produced and co-wrote its songs. Last year, he left the band, having informally withdrawn from its day-to-day activities in 2014. As a producer, Batmanglij has sought a wide range of collaborators. He has made an electro-soul record with a side project, Discovery, while producing giant left-field pop hits for singers such as Carly Rae Jepsen. He also produced tracks on Frank Ocean’s “Blonde” and Solange’s “A Seat at the Table,” and co-wrote a doo-wop- and lounge-influenced rock album with Hamilton Leithauser, formerly the lead singer of the Walkmen. Earlier this year, Batmanglij worked on Haim’s “Something to Tell You.” He gives the impression of someone who drifts from project to project, chasing challenges.

On a rainy August night, he was back in New York. We met outside a hotel in the East Village where he often stays. The steady growth of his career can be measured by the quality of his hotel rooms—he was delighted that this one had a sitting room. Batmanglij, who is thirty-three, has broad shoulders, and wears his hair short with a faint peak in the middle, hinting at a bygone Mohawk. He was dressed in a work shirt, a raincoat, and vaguely military-looking boots that made it seem as if we would be embarking on a long trek. We got as far as a Moroccan restaurant a few blocks away.

In 2007, when Vampire Weekend first began posting its music on MySpace and playing shows, the band’s crisp sound and polite, if esoteric, lyrics were difficult to assimilate into the indie landscape. The group’s academic pedigree was seen as a mark of inauthenticity. At a moment when much of New York rock still aspired to the greasy debauchery of the Strokes or the primal freakouts of Liars or Animal Collective, Vampire Weekend did not seem like a band that stayed up all night, fretting about personal liberation. I remember going to one of the group’s first shows, at the Mercury Lounge. The musicians were wearing “Seinfeld”-esque jeans and preppy cable-knit sweaters, and I told a friend that these were phenomenally good costumes.

They were kids who had grown up on the Internet, with few taboos about which musical traditions could be drawn upon to build rock songs. Instead of the grungy distortion that was then popular, they opted for the clean, jittery guitars of West African highlife, paraphrased rap lyrics, and synthesizer interpretations of dancehall rhythms. Popular music has always been culturally omnivorous. But Vampire Weekend’s pastiches conveyed a sense of breezy lightheartedness rather than self-gratifying discovery.

Later this month, Batmanglij will release “Half-Light,” his first album as a solo artist. He has been teasing at it since at least 2011, when he released a pair of singles, “Wood” and “Don’t Let It Get to You.” “Half-Light” is a wondrous album, full of coy dreams and quiet yearning. On “Gwan,” he confesses to a haughty, isolating self-confidence: “Don’t listen to me, I only believe myself.” But the majestic, seesawing strings hint at the peace and pleasures of letting someone else in: “And then I see you / The light falls through the room / And all of it don’t seem so hard.” Batmanglij sings gently, in a way that feels overwhelmingly intimate. He smears certain lines that seem too vulnerable.

In 2010, in Rolling Stone, Batmanglij came out as gay. His disclosure prompted a reassessment of his songwriting. “As a person who doesn’t identify as straight, any love song I write is contextualized by a queer identity,” he told me. Batmanglij is friendly and talkative yet difficult to know. Sometimes he looks uncomfortable, hands buried in his pockets, thoughts shielded by a stubborn grin. But his face instantly softens when you strike upon something he finds interesting and provocative, like a challenging interpretation of a lyric, or when you notice an easy-to-miss subtlety about his music, like the amount of time it takes for the drums to arrive on some of his best songs.

“It’s important to distinguish between my role in Vampire Weekend as a producer and my role on this album as a songwriter,” he said during dinner. “I think I had stories I wanted to tell that wouldn’t have made sense to tell in Vampire Weekend.” Many of the songs on “Half-Light” feel as though they could have become Vampire Weekend songs, except that they go somewhere else entirely. “My music is about identity. This album is about identity.”

Mohammad and Najmieh Batmanglij met in the late seventies, at a party in Tehran. They attended college in the United States. But after the Iranian Revolution, in 1979, they moved to the South of France, where Najmieh gave birth to their oldest son, Zal, who is now a filmmaker. The seeming rigidity of French society troubled them. They feared that their children would lose connection to their Iranian roots. The family moved to the United States, eventually settling in Washington, D.C., where Rostam was born, in 1983. Mohammad and Najmieh founded Mage Publishers, a small press devoted to Persian culture. For more than thirty years, Mage’s most popular sellers have been Najmieh’s pioneering cookbooks, which are devoted to the craft and traditions of Persian cuisine. (Rostam has taken over the design of his mother’s book covers. “You might see some familiar design tropes,” he said; they use many of the same fonts as Vampire Weekend albums.)

Iranian culture remained central to Mohammad and Najmieh’s American lives. They hosted poetry readings and musical performances at their house. Rostam went to the Potomac School, a prep school just south of D.C., which sits on ninety acres of gardens, woods, ponds, and streams. He recalls spending a lot of time outside, singing traditional songs with his teachers. The first song on “Half-Light” is “Sumer,” which is built around a sample of “Sumer Is Icumen In,” an Old English round that he loved as a child. He pointed out that the middle, instrumental passage of “Gwan” braids together elements borrowed from a Welsh lullaby and a Shaker hymn. “For me, those folk songs feel American,” he explained. He wanted to make music that mingled elements of his American upbringing with the Iranian and Middle Eastern textures and rhythms that he heard at home. “Wood,” a frolicking tune built on sitar, tabla, and strings, sounds like an inside-out version of one of the Beatles’ sixties excursions into Indian classical music. Throughout, Batmanglij plays a twelve-string guitar tuned like an Iranian instrument called a tar, which produces a plaintive, trancelike effect.

These gestures are so subtle that one wonders if anyone will notice. Batmanglij wants listeners to glean the mysteries and secrets of his songs, and how they were constructed, but he asked that I not reveal too many of the details he told me. Occasionally, he said, he goes through songs, such as “Rudy,” about a young boy’s sexual awakening, and deletes lyrics that give too much of the story away.