Seven years is how long Belle and Sebastian lead singer Stuart Murdoch was afflicted with chronic fatigue syndrome, a debilitating illness with no easy cure. You’re tired all the time, but sleep doesn’t help; you can’t hold a job down, since you don’t have the energy to be anywhere. Murdoch developed the disease as a university student, when he was old enough to fully comprehend what he’d be forgoing should his symptoms endure. Family? The hope of fame, or fortune? Forget about it.

If you imagine for a second how Murdoch must’ve despaired, then you’ll understand why he calls "Nobody’s Empire"—the opener on Girls in Peacetime Want to Dance, in which he sings about the solitude brought on from his sickness—the most personal song he’s ever written. That’s not a small statement, considering Belle and Sebastian’s reputation. Their ethos was crystallized in the title of the first song on their first album—"The State I’m In"—and they’ve spent nearly two decades staking their claim as the most sensitive band in indie rock, patron saints for daydreaming boys and girls. Their early records sounded feather-soft, but over the years, they slowly put on weight and become a real band, translating their bedroom aesthetics for the festival set.

On Girls in Peacetime Want to Dance, they’ve added a new wrinkle by writing an album that attempts to be pop qua pop, filled with synthesizers and dance grooves to coax their once notoriously-staid live crowds to cut a rug. Even the artwork is different: This is their first cover that doesn’t use a monochromatic photographic still that directly references the Smiths, their emotional forerunner. The band hired outside producer Ben H. Allen III (Animal Collective, Washed Out) to punch up their sound, and he encouraged them to take more chances. The band is confident enough to step into pro forma P-funk on "The Party Line" and polka singalong on "The Everlasting Muse" without losing their penchant for bookishness: "The Power of Three" name drops Sherlock Holmes and Moriarty, while the jaunty "Play for Today" mixes in chants of "author! author!" as Murdoch and Dee Dee Penny of Dum Dum Girls trade harmonies.

"Enter Sylvia Plath" combines both worlds, with a brittle rhythmic backbone giving the band their first song that you might—might—hear in a club. "The Cat With the Cream" and "Ever Had a Little Faith?" are both classic Sebastian, softly spoken songs where Murdoch reminisces for rainy days and childhood wonder. The piano line that kicks in during the latter’s outro is a pleasant little melody that accentuates Murdoch’s ear for nostalgic detail. So does "Nobody’s Empire", which Murdoch wasn’t lying about. It’s a nakedly autobiographical song that’s verbose even by their standards, with Murdoch spitting rapid-fire verses over a sleepy melody before letting loose with what passes for a scream in the Sebastian-verse, which is a place filled with indoor voices.

In an interview with the Daily Beast, Murdoch said he would’ve loved to be "a young Carole King," working in the Brill Building where so many of pop’s yesteryear hits were written. "I see no reason why that music can’t be possible again, but I look around and don’t see it," he said. "Sophisticated, nuanced, melodious pop music, that sweeps you away." That Murdoch’s shining ideal of pop harkens back to a half-century ago goes hand-in-hand with a lot of the band’s dandier affectations, as does his casual dismissiveness of today’s comparatively hedonistic Top 40. It's also strange because, to many long time listeners, the band already took their shot at writing a pop album with 2003's Dear Catastrophe Waitress and 2006's The Life Pursuit, where they churned out romantic hook-loaded singalongs like "I'm a Cuckoo" and "The Blues Are Still Blue", both of which are catchier and more memorable than anything on Girls in Peacetime Want to Dance.

Besides, Murdoch is surely trifling if he doesn't think sweeping, sophisticated pop has a place on the charts: Adele and Sam Smith are two singers who've carved their niche by singing right to your parents. A flippant comment to Pitchfork about how listeners would rather lose themselves in Nina Simone than Beyoncé shows not just a flagrant misunderstanding of how people listen to Beyoncé, but to the artists they love. He means well, but it faintly stinks of snobbery that's gotten other indie acts in trouble when they've tried to explain their theory of pop with, well, a lot of theory. Tom Krell of How to Dress Well raised hackles when he told Pitchfork he wanted to be "pop, but not populist." But what's wrong with trying to appeal to as many people as possible?

Girls in Peacetime Want to Dance reminds me of another recent attempt from a high-profile indie band to change directions. Arcade Fire surprised fans with the Caribbean-influenced Reflektor, their attempt at writing a looser, more playful album. They sort of looked like a bunch of dorks, but it didn't matter. Eventually, everyone learns what children and merengue instructors know to be true: Dancing is fun, regardless of how well you move your hips.

Look at the video of the band cutting through "I’m a Cuckoo" from the 2013 Pitchfork Music Festival. Murdoch hams it up, casting flirtatious looks from side-to-side, dropping to his knees like Elvis. At one point, he loses the guitar, because you can’t dance while holding a guitar. He’s having fun. And if fun is what he wants to have after 19 years and nine albums anointing them as kings of coyness and crossed arms—it’s hard to begrudge that.

And, who knows: Maybe this is the album to teach someone about fun. If not, it’s still a perfectly respectable hour of Northern soul-influenced pop, even if it’s difficult not to hear the intention behind every song. (Or to shake the feeling that a band like Cut Copy is much better at this shambling soul revue style of music.) One of Murdoch’s imaginary women instructs him to "be popular, play pop, and you will win my love" on "The Everlasting Muse", which sounds like noble inspiration but ends up falling short. You don’t win anyone by simply playing a pop song, or by deciding to be pop. It takes something else, something that can’t be explained by a mission statement. For a band so well-loved for writing from their heart, it sounds like they got stuck in their head.