Can you manufacture cool?

On the second stage at Lollapalooza in Camden, N.J., last weekend, indie-rockers Cave-In inspired a moshing free-for-all on the unforgiving tarmac. And right next door, ‘paloozers were playing baseball video games, getting in touch with their inner Jim Thomes and Randy Johnsons at batting and pitching cages, and wondering if that Sammy Sosa bat in the memorabilia trailer was corked. The Major League Baseball Roadshow is now back at Ozzfest.

What in the name of Willie Mays and Babe Ruth is going on? Is Kevin Millwood a closet Marilyn Manson fan? Is there some sort of synergy between home-run hitting and heavy metal?

The folks at MLB are doing their best to create some. It’s no big secret that baseball has an image problem: According to MLB, the average age of a ticket-buying fan is 45, and as of May, attendance was down 4.6 percent, on top of a 6.3 percent drop in 2002.

If you’re desperate to attract a younger audience, you use pop music. As MLB’s Carmine Tiso told me at Lolla: “We’re trying to morph the sports world with the entertainment world.” For MLB, some of that synergy already exists — Eddie Vedder recently dropped by the Vet clubhouse to hang out with David Bell. And hip-hop heads have long been down with Phillies gear thanks to the popularity of Philly Blunts cigars among discerning dope smokers.

But with the NFL, where U2 and the Dixie Chicks sing at the Super Bowl, and the NBA, where Allen Iverson wants to be a rapper and Jay-Z drops rhymes about Jordan and Yao Ming, the rock-and-jock mix couldn’t be more natural. For baseball, it’s a tougher sell, which is why the big leagues are reaching out to headbangers. The idea is to move merch, and build the MLB brand: “We’re aiming for the 16-to-24- year-old demographic,” Tizzo says. “They buy something because it looks cool, rather than to pledge allegiance to a team.”

Besides Ozzfest and Lolla, baseball has other ways to put the ball in play: The Ataris performed their remake of Don Henley’s “The Boys of Summer” before the home-run derby at All-Star Weekend in Chicago. Rollingstone.com’s “50 Baseball Moments That Rock” recalls historic instances ranging from the Beatles’ playing Shea Stadium to Madonna’s dating the now imprisoned Jose Canseco.

And though Bon Jovi recently played the final rock show at the Vet in Philadelphia, that doesn’t mean they’re not still cranking up tunes in the concrete doughnut. The Phils get the crowd stoked with all sorts of music, from the Spencer Davis Group’s “Gimme Some Lovin’ ” to a merengue tune called “Locamente” that attempts to drown out the jeers when Jose Mesa walks to the mound.

But there’s a preponderance of rock. On a recent Tuesday, girl-rockers the Donnas’ “Take It Off” was between-inning entertainment, and at a game last month I was stunned to see a video of New Zealand punk band the D4 interspersed with highlights on the Jumbotron, and hear Bow Wow Wow’s “I Want Candy” as the Phillie Phanatic danced with a human Hershey Bar and Reese’s Peanut Butter Cup on top of the dugout. And the Phils’ batters get to pick their music. Mike Lieberthal digs Creed, Thome grooves to The Who, Led Zeppelin and Boston, Bobby Abreu prefers salsa, and Pat Burrell is into Ozzy, who could probably do a better job at the plate than the beleaguered slugger has this year. (Let’s give praise that Millwood plays only every fifth game, since he opts for Toby Keith.)

All that raucous rock-and-roll makes the Vet a lively place, but it also underscores one of the biggest hurdles baseball faces as it attempts to shed its image as a nostalgia-obsessed dying sport. Notions of youth culture cool in music and fashion bubble up from the urban street, then get imitated on the suburban school bus. Baseball execs are aware of that: They’ll try to reach rap fans by bringing the MLB Roadshow along to the Sprite Liquid Mix tour in September. But, as Sports Illustrated reported last month, while Latino players make up 28 percent of the big leagues and white players have remained steady at around 60 percent, the percentage of African Americans has fallen precipitously to 10 percent, down from 19 percent in 1995.

So while Jimmy Rollins prefers to hear 50 Cent before taking his cuts, he’s well outnumbered. And a look around the Vet makes it obvious that, with a shortage of black players, the Phils are having a hard time drawing African Americans to games. Which means that this business of making the national pastime cool is going to be a difficult task. Baseball is a rock-and-roll game, but it’s a hip-hop world.