With a crowd of about 17,500, Jack and his crew kept the fans standing and singing along to all of his love-the-earth and you-can-make-a-difference lyrics.
Reverb, the non-profit organization that "greens" music tours, is looking for eco-conscious volunteers to man their Eco-Villages during some big name concerts this summer.
I set about asking some local business owners and a Bay area musician what songs or bands got their goat when they were growing up, and led them down the path to music.