The War on Drugs’ chief songwriter, Adam Granduciel, has a home studio in Philadelphia
full of vintage gear. (Kevin Faulkner)

If Adam Granduciel, the leader of The War on Drugs, wakes up at home in the middle of the night with an idea for a song, he doesn’t have to go far to put the idea to tape.

Much of the band’s third album, March’s “Lost in the Dream,” took shape in Granduciel’s Philadelphia home, where he has a makeshift studio. And even though the singer-guitarist spent eight months bouncing between professional studios while perfecting the album, home seemed to be the most fruitful — he even wrote one song in his kitchen and recorded another in his bedroom.

With a bevy of supporting players (culled from his touring band and Philadelphia’s indie-rock scene) adding to the mix, the album builds on the folksy, synth-rock of The War on Drugs’ breakout record, 2011’s “Slave Ambient.” It’s bigger, bolder and more assured.

“I’m in my finest hour,” Granduciel sings on “An Ocean in Between the Waves.” If that comes off like a boast, it wasn’t intentional. The line “was supposed to [be] more self-deprecating,” he says.

Perhaps he should reconsider: “Lost in the Dream” is easily The War on Drugs’ best work. With that in mind, Granduciel took Express on a tour of the album before Friday’s 9:30 Club show.

‘Under the Pressure’
Clocking in at eight minutes and 51 seconds, the opener is the album’s longest track — and it could have been even longer. “When I initially started it in my home studio, I was playing those two chords on the guitar and it sounded so sweet,” he says. “I put 13 minutes on the drum machine so I had enough room to jam. I was probably high and wanted to jam out on these two chords because I hadn’t written any words yet.”

‘Red Eyes’
The synth-y “Red Eyes” serves as a bridge between “Slave Ambient” and “Lost in the Dream” — it wouldn’t be out of place on the earlier album, but, like most of the new record, it just sounds bigger. Granduciel credits the increased musicianship of the album’s players for the sonic upgrade. “Any idea I had, musically, could be achieved between myself and everybody else,” he says, “and it just made things easy.”

With its slow pace and an ominous Rhodes piano part, “Suffering” is one of the album’s darker songs. “I actually recorded that by myself at home one night in 2012,” Granduciel says. “At the time, I wasn’t feeling that s—-y at all. I was just living fast, not thinking about much.” When the word “suffering” came out during a scratch recording, he “just knew the sound of a song called ‘Suffering’ was going to be this.”

‘An Ocean in Between the Waves’
After working on this track for a year, Granduciel had an epiphany: “It was a pile of garbage,” he says. With five days left before he had to hand in the finished record, Granduciel and the band reworked the song, cutting a noisy outro and tweaking the lyrics and music significantly. “Everyone thought I was crazy for wanting to rerecord,” he says. “But it ended up being one of a lot of people’s favorites.”

“Disappearing” began as a “free-floating synth jam” until friend Michael Johnson added a bass part using an Arp 2600 synthesizer that gave it more structure. The pair rebuilt the song from there, with Granduciel recording the guitars in his bedroom. “It sounds like water,” he says.

‘Eyes to the Wind’
“I wrote that song in four minutes in my kitchen,” Granduciel says of this folksy slow-burner. Yet it took him months to finish it. “I was really attached to that song,” he says. Lyrically nostalgic, musically anthemic, the song was his attempt at being “open and honest.”

‘The Haunting Idle’
Granduciel says this short, atmospheric instrumental “sounded like the mood of the album,” yet still stood out on its own. “That’s one take of me playing in the studio through seven amplifiers, so each amplifier had a different sound going through it.”

With bright synths, organ and acoustic guitars, “Burning” sounds a lot like Dire Straits, or Bruce Springsteen’s “Dancing in the Dark.” It’s a nice counter to some of the darker moods on the record. “I like making uplifting music,” he says. “I like having mellow songs and then total jam rockers.”

‘Lost in the Dream’
On the title track, Granduciel plays a vintage Fun Machine, which is basically an organ that’s also a drum machine. “I think they market it to people to put in their living room and have fun with it,” he says. “That was a simple song I recorded at home and built up over time.”

‘In Reverse’
“In Reverse” begins with an ambient passage that could be an extension of “The Haunting Idle.” “I work on stuff all together, so maybe I was playing the intro of ‘In Reverse’ and that informed this other thing I was recording,” he says. “I like that little things echo each other. It makes it a whole piece.”

9:30 Club, 815 V St. NW; Fri., 8 p.m., sold out; 202-265-0930. (U Street)