It’s one in the afternoon and the Do Good Bus is parked outside the 9:30 Club, right beside the tour bus of smash-hit indie band Foster the People. While the band is inside warming up, excited volunteers climb on-board, not knowing quite what they are getting themselves into. Inside, paper lanterns are strewn about, and board games and kids toys are stuffed into overhead compartments. Foster’s album, Torches, plays on loop.

The nonprofit disguised as a decked-out bus brings together participants in a party-style ride and takes them to a mystery volunteer site. Riders don’t know exactly where they’re going or what they’ll be doing.

A FEW YEARS BACK, Los Angeles locals Rebecca Pontius and Stephen Snedden volunteered at a nonprofit that was beautifying L.A. metro stops. They enlisted the help of Rebecca’s kid brother Mark Pontius and his then-undiscovered band, Foster and the People, to jam out at one of the stops.

Now re-dubbed Foster the People, the indie-pop trio has gone from playing for under ground audiences to more high-profile stages across the United States and the world.

“Pumped Up Kicks,” their electro-pop single, went viral and catapulted the group into the blogosphere, making them the buzz band of the summer. The rest of their album made the Billboard Top 10, with “Kicks” reaching Platinum.

Despite their meteoric rise, members of the band haven’t shaken their do-good roots.

“We always wanted to do something with charity from the get-go,” drummer Mark Pontius says. “When we first started the band we thought, ‘Every penny we make, let’s try to put it to a good cause somewhere.'”

But rather than just writing a check, the group once again teamed up with Rebecca and Snedden, who then co-founded the Do Good Bus.

“It was inspired by volunteering … and birthday party buses,” Rebecca says with a laugh. She and Snedden had been working in different organizations around L.A. for years, and friends were always asking the pair how they could get involved in volunteer work.

“We always say ‘Just do it, just go volunteer,'” she says. But newcomers didn’t always know where to start. Then last August for Rebecca’s 30th birthday, a group of pals rented out a party bus to celebrate, bringing together friends of friends as well as regulars in the local volunteering circuit.

“It was all people who didn’t know one another,” she says of the strangers who got to know each other and move freely about the party bus. “And then [Snedden and I] thought, what if we put people on a bus and took them to a volunteer activity and says, ‘Here’s how you do it,’ and have fun at the same time.”

When Foster the People kicked off their “Foster the Future” tour, they used their newfound star power to get the Do Good Bus’s wheels moving and onto the road with them. Mark says he was “floored” by his big sister’s idea, as it fit with a band that sought, literally, to foster the people.

“We’re interested in trying to do things differently,” he says of the band’s mission.

“This Do Good Bus was such a cool idea because nobody has done that before. It’s just a different idea of helping people, and we’re more turned on by that, because any big band can just take money and put it somewhere, and say ‘Here, now do it.’ But we really wanted to dig in and do something great and realize it as a team.”

To give their idea some traction, the band helped raise $130,000 from fans in less than a month. Donating fans were rewarded with band “swag,” such as signed drumsticks, their picture on the back of the bus or personalized postcards sent from the road.

Upgrading from a yellow school bus, the party bus was tricked out with the band’s logo and Torchesalbum art. The band and the bus began their 24-city sweep this September in Santa Ana, Calif., traveling cross-country to cities like Austin, Texas,  Atlanta, Ga., and Richmond, Va. before rolling into D.C. This Monday, the group sold out two back-to-back performances at the 9:30 Club

SNEDDEN AND JOHN GRINDLE (the official “Do Good Bus High-Five Guy”) are leading an icebreaker with the fans, who range from high schoolers to young professionals. Most discovered the project through the band’s website — clearly huge Foster fans. To get on board, they filled out an online application with the question of what “community” means to them.

“We weren’t looking for someone who strictly wanted to meet the band. We were looking for people who love the band and want to volunteer,” Snedden says. In fact, there’s no guarantee that the volunteers will even get to see the band. But, Rebecca says with a smile, the members like to come by and meet the bus if they finish sound check in time.

As the Do Good Bus pulls out of the venue’s parking spot, Rebecca, Mark’s older sister, tells the participants more about the mission of their organization.

“We have three goals with the Do Good Bus: The first is to create awareness for people here locally so they can find out about causes where they can give back,” Rebecca says.  “Second goal is to create community on the bus as well, as when we’re at the activity and we want to pull like-minded people together and have them meet in the city.

“And our third goal is to encourage continued support of volunteering in general. It may not be the cause you went to today, but we want to inspire people to give back in some way.”

Driving through the District, participants still don’t know where exactly they’ll be going or what cause they’ll be serving. Why the mystery?

“It’s just fun,” Snedden says with a laugh. “Part of the surprise is, because you don’t know what you’ll be doing, you can’t be scared of it, and it also encourages people to try things [that] maybe they wouldn’t have done. We’ve gotten people involved in organizations that they had no idea they would enjoy or want to do again.”

Today’s trip includes both veteran volunteers as well as 16-year-olds who came in hopes of meeting the band.

“We’ve gotten a younger group of volunteers, because of Foster the People’s fan base. Hopefully we’re reaching people at a crossroads, where they’re being introduced to volunteering, and this is their first chance, so we’re making it fun for them.”

THE MYSTERIOUS LOCATION IS REVEALED as the bus slows to a stop, dropping the Do Gooders off at Meridian Public Charter School in Northwest D.C. Today they’ll be working with The Grassroots Project, founded by alumna Tyler Spencer (GRD ’09), which pairs student-athletes with urban youth to educate them about the risks of HIV/AIDS.

Spencer came up with the project after he volunteered in South Africa for a similar program, Grassroots Soccer, which pairs professional soccer players with at-risk youth. When Spencer came back to the states, he realized that with one in 20 residents HIV positive in the District, the situation here wasn’t far from South Africa’s.

“I thought it’d be really cool to take this model and implement it in D.C.,” Spencer says. “At the same time, I also felt that in addition to the kids being influenced positively by college athletes, the athletes had a lot to gain by getting out of the Georgetown bubble and into the community.”

Starting with 40 Georgetown athletes working with three middle schools in 2009, the initiative has grown in three years to serve 33 schools with over 300 athletes hailing from the Hilltop and District locals Howard University and The George Washington University. Georgetown’s project targets 11- to 14-year-old middle school students, aiming to educate them before they reach the critical demographic age group —14 to 21 — that is most affected by the virus.

“We want to reach these students before they turn 14, before they take risks or make choices,” Managing Director Deidra Sanders (SFS ’11) says. “We don’t try to tell them what choices to make, but we try to give [them] the information to make good choices.”

Lessons range from the risks of certain choices to how to build a support network. The “Do Good Bus” crew has made it to the first session of the semester, so the lesson is a little lighter — a game of speedball. For the group of eighth grade boys, the game quickly turns into a fast-moving competition.

“In the first couple minutes, everyone’s all shy and timid because today was our first session, but after five minutes, it’s all gone,” says Sanders. The Do Good volunteers throw themselves completely into the game, with each team shouting out to their players nicknames like “Wizz” and “Moussie,” because Grassroots encourages the kids to be who they want to be, including their names.

At halftime, group coordinator Matt Mullman (COL ’13) asks the kids what they’ve learned and what they can improve on. Eventually this leads to a discussion about listening to advice and to “coaches” in life. When college athletes guide the kids, it proves more effective than when traditional authority figures teach them, says Spencer.

“You see the types of people doing HIV prevention education, and a lot of them are school nurses and older people, who have good intentions; but when we’re talking about an issue like this, you need to be able to connect with the kids,” he says.

Mullman, or “Matty Boy,” his nickname of the day, says that simply playing with the kids is the most rewarding part of the program. “I found that through sports, they really pick up the messages well, and they have fun doing it, and so do I,” he says.

“You just get to be a kid for an hour and half.  You just get to be in eighth grade again, and if you can do that, you can work with them,” Connor Smith (COL ’14), or “Cookie,” according to his nametag, says.

Spencer credits the program with teaching not only the kids, but the student-athletes as well. Program participants have gone on to work with Teach for America and other public service organizations after graduation.

“I think alot of college athletes can go through college with their sport being a part of their identity, and so being able to bridge sports, like we do in this program, with real life is helpful connection for them to make,” he says.

AFTER A DAY OF VOLUNTEERING, the Do Good Bus pulls up to 9:30 Club once again, and Foster the People has just wrapped up sound check. Early arrivers, mostly teenagers donning skinny jeans, are wandering to the venue, looking at the Foster-decorated Do Good Bus and hoping to catch a glimpse of the band.

Rebecca and Snedden, slightly sweaty after the intense speedball game, are gregariously meeting up with the crew and saying good-bye to the volunteers. Snedden offers the volunteers­­­ homemade brownies. (“Fans make us stuff all the time!” Rebecca says.)

“We’ve been really excited about seeing how the volunteers respond,” Rebecca says, reflecting on the day. “They come into it not knowing anything and come out of it thinking ‘Oh wow, that was actually really awesome,’ and they might do it again.”

The Do Good volunteers are lingering around the back of 9:30 Club, waiting to hear from Rebecca whether the band has time in between sound check and that night’s performance.

When Mark breezes out of the venue, the starstruck volunteers grow quiet and then rush forward to ask for pictures and autographs. Off to the side, Rebecca observes her little brother posing for soon-to-be-uploaded profile pictures with fans.

“For me, it’s almost an excuse to be on the road with him,” she says. “We also have the same mentality for what we want out of this.”

And that do-good, feel-good mentality has worked well. Touring together, they’ve traveled over 9,880 miles with 750 volunteers in 24 cities.

“You always hear that big artists try to do big things because they have a big footprint,” Mark says. “I wasn’t aware that we could do that. That we could raise money through the band for something good.”