Kevin Mazur

Vocalists remaking “We Are the World” include Wyclef Jean, foreground; Barbra Streisand; LL Cool J, back left; and Jeff Bridges, back right.

It’s one measure of the slippage between the original and the remake,  or downloaded from iTunes. By Sunday morning it was the No. 1 single on iTunes and had been viewed on YouTube four million times.

“We Are the World” was written by Michael Jackson, whose portions from the original song and video clip are reused, and by Lionel Richie, who organized the 2010 version along with the original producer, Quincy Jones. They took on new-generation collaborators: Lady Gaga’s producer, RedOne, and Will.i.am, who joins the songwriting credits by adding rhymes for rappers. The song itself, for all its Hollywood gloss, has turned out to be durable. A gospelly lift in the chorus saves the lyrics from their potential narcissism — “We’re saving our own lives” — to insist that all the stars are indeed singing about worldwide community.

A 25th anniversary remake had already been in the works, timed to the availability of stars in Los Angeles for theGrammy Awards at the end of January. When the earthquake hit Haiti on Jan. 12, the song acquired a new and immediate cause and a central performer: Wyclef Jean, the Haitian-American songwriter, singer and rapper from the Fugees and one of the remake’s producers. His spot leaps out of the video clip: singing in English and Creole, he ululates in a way that reaches back to Afro-Haitian roots. It’s a premeditated moment but a passionate one.

The good intentions are clear and laudable. May the song and video draw donations. But as a piece of work, “We Are the World 25 for Haiti” has all the pitfalls of a Hollywood remake. It whipsaws between attempting a shot-for-shot homage to the original and giving it some new twists. The video’s director, Paul Haggis(who made “Crash”), added one major improvement on the 1985 clip. He included images from outside the recording studio, from Haiti, where scenes of ruin and relief work give way to smiling, hopeful children under the Caribbean sun. While the stars still get their close-ups, now they have a context.

Still, “We Are the World 25 for Haiti” rises or falls on its talent pool. As in 1985 the song features current chart-toppers along with a few elders, like Tony Bennett and (on guitar)Carlos Santana. It turns out there’s a major gender gap. The women can nearly hold their own against 1985: Jennifer Hudson, Pink, Barbra Streisand, Mary J Blige, Celine Dion, Toni Braxton, Jennifer Nettles (from Sugarland) and Nicole Scherzinger (from Pussycat Dolls) can rival the lungpower of Dionne Warwick, Tina Turner, Diana Ross, Kim Carnes and Cyndi Lauper from 1985. They’re not always deployed as wisely, though, especially when the new version follows Ms. Streisand’s warmth with the teenypop nasality of Miley Cyrus.

And the men — well, the lineup unfortunately speaks for itself. Justin Bieber in place of Lionel Richie on the opening verse. Josh Groban for Kenny Rogers — actually, that’s a toss-up. Simperers like Adam Levine (from Maroon 5) and Enrique Iglesias appear rather than Stevie Wonder. Usher openly mimics Michael Jackson. And there’s an Auto-Tuned triumvirate: not just Lil Wayne but Akon and T-Pain as well, all in a row. (Mr. Bieber also sounds slightly computer-assisted, or maybe I’m just suspicious.)

Back in 1985 the pop charts gave “We Are the World” male stars like Bruce Springsteen, James Ingram and Willie Nelson, and even the cornballs — Steve Perry of Journey, Kenny Loggins, Huey Lewis — could sing. The remake’s most embarrassing moment is the spot where Ray Charles arrived in 1985 — off-camera at first, but absolutely unmistakable. NowJamie Foxx trots out his Charles imitation.

That’s not the only part of “We Are the World 25 for Haiti” that suggests big-name karaoke. Michael Jackson’s first ghost appearance in the video, where he was juxtaposed in 1985 with Ms. Ross, now has him joined by Janet Jackson instead. Ms. Dion mechanically copies the octave-spanning arpeggio that Ms. Lauper used for a spontaneous jolt in the original. Many of the singers sound daunted by their predecessors, and rightfully so.

Eras change. In 1985 rock ruled pop, and R&B was determined to cross over. In 2010 rock is barely on the map, and R&B and hip-hop define pop. Where the first “We Are the World” headed into its finale with fervent, improvisatory call-and-response duos — Mr. Springsteen and Mr. Wonder, Mr. Ingram and Mr. Charles — the anniversary version switches over to rapping, with solo spots from Kanye West and Will.i.am and a group led by Will.i.am, (adding more star names to the roster of performers) for some serviceable rhymes: “Someone to help you move the obstacles you stumbled on/Someone to help you rebuild after the rubble’s gone.”

It’s as dutiful as it is sincere, but it’s not a peak. For that “We Are the World 25 for Haiti” makes a bold move: ending with just voices. The studio choir belts the chorus, images of Haiti (including the long trumpets and drums of Haitian carnival tradition) fill the screen, and Mr. Jean chants “Haiti, Haiti.” Finally the song no longer looks back.