(CNN) -- Singer-songwriter Jack Johnson released a new album on April 17 in honor of Earth Day called "Jack Johnson and Friends: Best of Kokua Festival." It's a collection of live highlights from the festival over the years featuring some legendary names in music: Willie Nelson, Jackson Browne, Eddie Vedder and Dave Matthews.
But the album is about more than just music. The proceeds from both the festival and the album go back to Johnson's Kokua Hawaii Foundation to promote conservation efforts in Hawaii.
Johnson and his wife, Kim, are natives of Hawaii, and for years they have been champions of conservation, environmental awareness and education both in their native state and around the world.
"We decided to create the foundation because I stole my wife away from teaching geometry and she became my first tour manager, and ... she wanted to be involved in education again." Johnson said. Their foundation got them both back into Hawaiian classrooms.
The Kokua Hawaii Foundation supports environmental education in schools and communities throughout Hawaii. The main programs the foundation has implemented since its creation in 2003 promote recycling and taking children out of the classroom and into the environment for hands-on learning experiences. Most recently, the foundation introduced the Plastic Free Schools program to reduce single-use plastic on the Hawaiian Islands.
"The Kokua Hawaii Foundation's programs are really hands-on and get kids out into nature. Usually, they are having so much fun that they don't realize how much they are learning," Johnson said.
To raise money for the foundation, the Johnsons created the Kokua Festival in 2004. The festival is held every year on Earth Day weekend outdoors in Honolulu's Waikiki Shell. Johnson brings in friends in the music industry who share his passion for environmental preservation.
"All of the musicians who've played at the Kokua Festival have a connection to the cause and the work we are doing with the foundation," Johnson says. "The musicians themselves were a big inspiration for the foundation from the start -- like how Willie Nelson runs his tour buses and trucks on biodiesel and how Eddie Vedder has been active in several environmental causes."
"For me, it's wonderful to get the chance to play with these musicians I respect and have loved for years, to share some great music with them and use that music to help raise funds we need to keep Kokua Hawaii Foundation's programs going. Hopefully, that inspiration goes both ways, and the musicians who join us will implement some of the greening measures from the festival into their own tours."
In addition to the music, the festival also continues in the educational tradition of the foundation. More than 50 eco-friendly businesses and local environmental groups set up shop in the Kokua Village, which is much like what Johnson does on tour. Here, the fans can learn about sustainable products, watch alternative energy demonstrations and sample local food and beverages.
Another element that mirrors Johnson's efforts on tour: There are free water refill stations to encourage the use of reusable water bottles.