Justice and Soulwax have a lot in common. Both have released tour documentaries this month: Soulwax's Part of the Weekend Never Dies and Justice's A Cross the Universe.

Both are world-touring, stadium-sized acts that straddle the (now tedious) line between rock and electro. Both play each other's songs live, remix each other, and perform at the same parties. And both run in similar, overlapping circles—the director of Justice's film (So Me) animated the intro to Soulwax's (which is directed by Saam Farahmand of that "girls making out with each other" Simian Mobile Disco music video); Justice make an appearance in Soulwax's doc (in which they cop to having sampled Soulwax's drum sounds for many of the tracks on their record). But stay in on some slow, dead winter weekend when there are no parties to go to, watch both these films, and you will observe a world of difference.

For one thing, while both films are pretty standard "behind the scenes" tour documentaries, A Cross the Universe consists solely of such footage, while Part of the Weekend benefits from the inclusion of interviews with James Murphy, Nancy Whang, and Tiga, all of whom are smart and funny and provide essential context for the Belgian band.

Part of the Weekend (named for a Soulwax lyric) follows the group around the world on their Radio Soulwax tour, which includes DJ sets from 2 Many DJs and performances from Soulwax Nite Versions (the confusing taxonomy of this tour is all sorted out in the first few minutes). A Cross the Universe (a play on the name of the recent Beatles musical as well as a reference to Justice's reverence for the cross) follows the French duo and friends across only North America. The contrast is startling: While Soulwax come across as natural jet-setters, whether visiting friends in New York or appearing amiably on an oversexed Latin American television show, Justice seem equal parts enamored of and entirely out of water in America, eating giant cheeseburgers, trying to order "what-air" instead of soda at the drive-through, posing with Hooters waitresses, shopping for multimillion-dollar beachfront properties in L.A., and ultimately brushing up against the law due to one of their entourage's obsession with and possession of easily obtained American firearms.

As much as both films are documents of these groups' shows, they're also essentially advertisements, and in this regard, Soulwax's is the far more effective film. Their shows, club nights, and parties appear full of beautiful, well-heeled, and, aside from a little drug-addled babbling (naturally set to the tune of Soulwax's "E Talking"), well-behaved revelers. Given your tolerance for high-rolling hipster waifs with foreign accents, this is the kind of elite yet populist party you want to be at. Justice's shows, on the other hand, look like Nazi youth rallies, only violent (particularly frightening is one slow-mo shot of a shirtless, buff, blond dude hulking the fuck out in the front row of one concert), and their fans are portrayed as screaming, drunk, idiotic d-bags. Advertisement fail.

Another contrast is that while both Justice and Soulwax split their performing between "DJ" and "rock" incarnations—Soulwax via the aforementioned aliases, Justice by simply DJing after some shows (although no such DJ sets are shown here)—Soulwax's rock show is the real deal. The band—on live drums, bass, keyboards, and vocals—simply tear through the "remixed" (nite) versions of their songs as well as covers of their friends' songs (including Justice's "Waters of Nazareth"). Justice's show, on the other hand, is something more like a pantomime, with the duo backed by nonfunctioning prop amplifier stacks and surrounded by (again, purely ornamental) blinking "synth" racks. At the heart of the operation are only a couple CD players and a mixer.

Not that A Cross the Universe is entirely without merit. The scene in which Justice's Xavier De Rosnay sings "Under the Bridge" to a bemused-looking Anthony Kiedis is worth watching, as are the scenes with Justice's tour-bus driver, a sincerely religious man named Roger who's honing his baritone in an attempt to win the world record for lowest vocal note ever (I would not be surprised to learn "Roger" was actually Christopher Guest with an expensive fake face).

The most revealing scene in the film, though, might be one in which De Rosnay plays a melody at a piano with his hands obscured by the camera angle; when he takes his hands off the piano to pick up his cell phone, the melody keeps playing. Watching Part of the Weekend, you get some impression of Soulwax as people; watching A Cross the Universe, all you get are Justice's mostly silent, cigarette-smoking faces, their leather and denim facades, and the nagging tension of wondering what about them is "real" and what is "fake." Or maybe it's just that Soulwax seem, you know, nice, while Justice seem like (real? fake? who cares?) assholes. recommended