A generation ago, the unofficial motto for musicians on tour was "sex, drugs and rock and roll."

For a growing number of players today, that has changed to a less dangerous and much more eco-friendly mantra:

Reduce, reuse and recycle.

Led by stars like Bonnie Raitt, REM, Neil Young, Jack Johnson, Willie Nelson, Maroon 5, Barenaked Ladies, Pearl Jam, Nelly Furtado, Dave Matthews Band, John Mayer and an organization called Reverb, artists are doing what they can to become "carbon neutral," which is not an easy task in an industry marked by excess that requires cross country travel.

Aimee Mann, who plays June 13 at the Pabst Theater has been striving for carbon neutrality for some time. 

Environmentalists say achieving carbon neutrality requires two steps. The first is to reduce carbon emissions through familiar conservation measures such as replacing incandescent light bulbs with fluorescent, using public transportation and other common measures. The second step is to buy "carbon offsets" by sending money to projects that replace fossil fuels with renewable energy sources or to projects, like tree farms, that remove carbon dioxide from the air.

Adam Gardner, a member of Guster founded Reverb along with his wife, environmentalist Lauren Sullivan, in 2004.

"The environment is on the forefront of everybody's mind right now," Gardner told Reuters news service in a recent interview. "Our job is to keep it there until it's no longer a problem."

Reverb has helped more than 50 concert tours become more "green" by stressing the use of biodiesel fuel and other measures, such as creating eco-villages at concerts.

"It's not a trend," Gardner said. "It's something that has been building momentum for a long time. And now that we're seeing the actual effects, more and more people are becoming aware and want to take action.

"So we're just trying to help people, whether they're in a band or a fan of the band. It starts with the artist and reverberates out to their fan base."

Reverb urges bands and promoters to analyze every aspect of the concert experience and search for ways to reduce the carbon footprint. Fans are urged to carpool to venues and drink out of reusable water bottles. Tickets are printed on recycled paper. A new program may eliminate tickets by sending a text message with a barcode to a cell phone, which could be scanned at the gates.

Bands also use "green" guitars and rechargable batteries onstage and ask for biodegradable cups, plates and silverware backstage and power generators with bio-diesel fuel. For non-stage lighting, some venues are using solar-powered light poles or fluorescent paint.

Here is video of Gardner talking about Reverb: