The Roots' Ahmir "Questlove" Thompson and his bandmates are just one of many bands curating their own fesitval this summer. (AP Photo/Matt Rourke)

Hip-hop vets the Roots will throw the fourth annual Roots Picnic in Philadelphia on June 4. Chicago rock-folkies Wilco will host the second annual Solid Sound festival in western Massachusetts from June 24 to 26. And Pearl Jam will celebrate 20 years of bandhood with a two-day festival in East Troy, Wis., on Sept. 3 and 4.

With each festival come heaps upon heaps of supporting acts, all handpicked by the respective headliner. It’s a chance for some of the biggest names in music to surround themselves with their heroes, their heirs and their friends.

Is it the Facebookification of popular music?

“People want to connect with an artist,” says Glenn Peoples, senior editorial analyst at Billboard magazine. “They want to enjoy the same music that an artist enjoys. . . . They want to experience bands that are all friends, that are all part of the same social network.”

With every passing summer, we want to feel closer to our favorite touring acts. We not only want them to be our pals, we also want to meet their pals. And so they become our Sherpas, ready to slash through the bloggy bramble and lead us to kindred musicians worthy of their endorsement.

That feels most evident in the case of the Roots, a group that can be seen canoodling with different pop musicians every weeknight. They’re the house band on “Late Night With Jimmy Fallon,” a show that offers the most adventurous music programming on television.

The group threw its first Roots Picnic in 2008, the summer before “Fallon” hit the airwaves. This year’s event again takes place at Penn’s Landing in the group’s native Philadelphia. The bill features rap heroes young and old Wiz Khalifa and Nas, respectively), but the undercard is refreshingly hip. Jazz princess Esperanza Spalding, neo-glam troubadour Ariel Pink and Swedish soul troupe Little Dragon are scheduled to appear, and all— surprise!— have appeared on “Late Night With Jimmy Fallon.”

Also performing are recently re-formed Dismemberment Plan, the Washington post-punk group that was invited to play the Picnic moments after it performed on “Fallon” in January. Plan bassist Eric Axelson says he admires the spirit of the festival. “It’s like, ‘Here are bands we like,’ ” he says. “‘Come check it out.’”

And the love is mutual. “I’ve been a Roots fan for a while,” Axelson says. “[The Picnic] has always had a good mix of hip-hop and rock and everything in between. . . . It’s a cool lineup.”

Wilco’s Solid Sound festival will include acts such as Levon Helm and Thurston Moore. (Kyle Gustafson/FTWP)

Dubbed the Dave Matthews Band Caravan, these massive bills read like a movable Bonnaroo festival. Ray LaMontagne, the Flaming Lips, Michael Franti and Spearhead, O.A.R. and David Gray have each signed on for the first two Caravan stops and will be joined by dozens of other acts. For the second two festivals, Matthews will be joined by Dispatch, Gogol Bordello and, actually, the Roots.

The bill at Pearl Jam’s PJ20 festival isn’t huge, but some of the names are. The Strokes and Queens of the Stone Age will help fill out the top of the bill. Pearl Jam will use the opening slots to endorse under-sung veterans (Mudhoney, John Doe of X) and give a boost to younger unknowns (the Young Evils, Star Anna and the Laughing Dogs, thenewno2).

Wilco’s Solid Sound festival in North Adams, Mass., appears to be taking a similar tack. The bill includes rock legend Levon Helm, Sonic Youth leader Thurston Moore, and indie buzzbands Sic Alps and Purling Hiss.

“The band just wanted to do something fun with their friends and the bands they love in a sort of nice summery place,” says Wilco manager Tony Margherita. “You have people’s attention for a few days. Musically and otherwise, it becomes much more of a communal thing. You’re not just popping in and out of people’s lives. You’re actually spending some time with them and having a conversation.”

That fan-centric approach seems like a smart move in a challenging summer touring market. According to Pollstar, a trade publication that tracks the health of the concert industry, the top 50 tours in North America grossed 15 percent less in 2010 than in 2009. Ticket sales, meanwhile, dropped 12 percent while the total number of concerts dropped about 3 percent.

Peoples at Billboard thinks this might be part of the reason why we’re seeing a bump in artist-curated festivals. “Sometimes, just going out on tour isn’t enough,” he says. “There’s a lot of competition.”

And next summer?

“I expect that we’ll see more of it,” he says. “It’s a great innovation to keep people interested in live music.”