Rock in Rio: Five acts to make it worth the trip to Las Vegas

The dozens of acts on the bill for the inaugural Rock in Rio USA festival, scheduled to take place over the next two weekends in Las Vegas, are divided into two categories: the rockers, set to perform May 8 and 9, and the pop stars, on deck for May 15 and 16. Yet these artists can also be sorted in a different way: those that are worth the schlep to yet another music festival and those that aren’t. Here are five to justify your trip.

The Pretty Reckless, 8 p.m. May 8

Best known as that rock band featuring a cast member from “Gossip Girl” — remember “Gossip Girl”? — the Pretty Reckless benefited early from that association but now seems doomed to live with it forever. Still, don’t underestimate Taylor Momsen, who played the duplicitous Jenny Humphrey on that late-2000s teen soap: Armed with her bratty sneer, her slashing guitar and a deep bag of crunching hard-candy tunes, she’s more convincing in this role than she ever was on TV.

Metallica, 11:10 p.m. May 9

The heavy-metal giants are at work on a new studio album, their first since 2008’s surprisingly fierce “Death Magnetic.” Before they finish the record, though, they’re headed out for a handful of concerts around the world, including a headlining performance here. Drummer Lars Ulrich has said Metallica’s set list may include new songs. But that’s a less exciting prospect than hearing the band thunder through its still-potent oldies in the open air.

Tove Lo, 4:30 p.m. May 15

An experienced Swedish songwriter who broke out on her own last year with her hit “Habits (Stay High),” Tove Lo roughs up high-gloss Top 40 pop with frank accounts of her adventures with sex and drugs. “Queen of the Clouds,” her strong 2014 album, reflects a serious studio talent. But recent live shows suggest she’s developing her real-world swagger too.

Taylor Swift, 11:10 p.m. May 15

The pop megastar launched her new world tour this week in Tokyo, but it’s not due in these parts until August (when she’ll do five nights at Staples Center). So here’s an early chance to see how Swift is bringing the synthed-up sound of her smash “1989” album to the stage.

Big Sean, 5:30 p.m. May 16

Oddly low on hip-hop talent, Rock in Rio’s only marquee rapper is Big Sean, a selection that might’ve triggered groans just a few years ago. But the Detroit native (and former protégé of Kanye West) has come a long way since his days as a self-promoting irritant. Actually, he’s still a self-promoting irritant, but now he seems to be having some fun with the job.