Willie Nelson is taking time from his own tax problems to help with the Earth's problems. Nelson, Bruce Hornsby & the Range and 10,000 Maniacs were among the acts headlining Saturday's Earth Day benefit concert in Foxboro, Mass. "Other people's problems are as important as mine and to them they're a lot more important," said Nelson. The singer, who recently sold his Texas farm to pay off part of his debt to the Internal Revenue Service, also has been very active in Farm Aid. Other performers lending their talents to protect the environment Saturday were Rosanne Cash, Jackson Browne, Bruce Cockburn, KRS-One, Queen Latifah, Billy Bragg and Indigo Girls.