It’s official: Arcade Fire are indie rock legends. The Montreal-based collective that brought you the millennial magnum opus of 2004’s “Funeral” now have an Album of the Year Grammy under their belt and pop up regularly on “Saturday Night Live.” Their latest album, “Reflektor,” is their first release as true megastars—or as close to megastars as a French-Canadian baroque-pop-meets-punky-art-rock outfit can be—and they’ve tried their best to back up their stardom by pulling out all the stops on the new album.

Indeed, though they’ve always been characterized by grandiose gestures, “Reflektor” is the band’s biggest and most eclectic undertaking yet. Labyrinthine viral marketing campaigns aside, the double album’s 13 tracks tackle themes ranging from Haiti to Kierkegaard and feature production work from another indie icon, LCD Soundsystem maestro James Murphy. But while Arcade Fire are capitalizing on their newfound fame, they also seem uncomfortable with it, and unfortunately, there’s a good chance their fans will soon share this ambivalence. Yes, even though it’s no debacle, “Reflektor” is the first true disappointment of the band’s career, for even as it features a solid helping of epic Arcade Fire-ness and slickly produced grooves, it’s also overlong, disjointed, and lacking the anthemic power of the group’s best work.

“Reflektor” continues the Arcade Fire tradition of dealing with every event in the grandest of terms, no matter how personal. Coping with paparazzi is, to frontman Win Butler, a spiritual battle; on “Flashbulb Eyes” he sings, “What if the camera / Really do / Take your soul / Oh no.” And “Afterlife,” for which the music video features a sequence from Marcel Camus’s 1959 film “Black Orpheus,” lends a mythic guise to the aftermath of a romance. “After all the breath and the dirt and the fires are burnt,” Butler pleads with his wavering tenor, “Can we work it out?”

What unites these various themes is a pervasive feeling of aloneness. But the pain of the lyrics often rings hollow when paired with the album’s sleek, dance-ready disco aesthetic. The title track is an anguished chronicle of isolation in the digital age, but you wouldn’t know that from its tight Blondie-esque drums and stabbing saxophone riffs that seem crafted for a nightclub audience. The song’s ear-catching fragments—its snappy “just a Reflektor” hook, for instance—are just that: short digestible phrases that a liquored-up audience can grab onto while bobbing along to the solid but repetitive beat. The song simply isn’t an adequate vehicle for its heavy content.

Elsewhere on the album, though, Murphy’s electronic touches work to expand the already cinematic Arcade Fire sound. The refrain of “We Exist” would be at home on any of the band’s projects; twinkling piano lines spar with jagged violin interjections over a guitar texture with just enough classic-rock distortion. But Murphy kicks the track up a notch, adding a deep, buzzing bass and reverb-heavy drums that build to a well-earned release.

Murphy may be the album’s marquee guest star, but its most thrilling moments actually come from Butler’s wife, singer Régine Chassagne, who is woefully underutilized as a vocalist. While her solo songs rank among the highlights of the band’s past albums, she is here relegated mostly to the background. When she does pop in, though, she’s glorious, saving weaker tracks from total failure. “Normal Person” is a generic guitar-driven rocker, but Chassagne pierces its overwhelming fuzz with an uplifting, angelic interlude that steals the otherwise boring and unoriginal song.

Even as “Reflektor” shows flashes of excitement, there’s no truly great song on the album. The rousing shout-along chorus of 2004’s “Wake Up”? The percussive, satirical hook of their last album’s “Rococo”? “Reflektor” has no moments like these. Too many tracks show potential and fail to deliver, a fault that carries over to the whole album. Sure, the material will make for a great live show. It’ll probably get some decent airplay, too, with the few hooks it has. And hey, at least they’re still experimenting, right? That question might excuse a lesser band, but this is Arcade Fire in 2013. They’ve stepped out of their neighborhood, out of the suburbs, onto the world stage. They’re indie rock legends, and they’re better than this.