Jack Johnson will be joined by Ben Harper and Willie Nelson and the Planetary Bandits at his third annual Kokua Festival.

Jack Johnson will be joined by Ben Harper and Willie Nelson and the Planetary Bandits at his third annual Kokua Festival. The event will be held April 19 at Maui's Arts and Cultural Center and April 22 (Earth Day) at the Waikiki Shell in Honolulu. The lineup also features Henry Kapono, Paula Fuga and Animal Liberation Orchestra.

Proceeds from the shows will benefit the Kokua Hawaii Foundation, which works to preserve Hawaii's natural environment. Some funds have been earmarked to expand recycling programs in schools, sponsor field trips and curriculum development.

Local environmental groups will be on hand at both shows, which will also offer local organic food vendors, childrens' activities and goods purveyed by environmentally friendly, Hawaii-based companies.

Tickets go on sale Feb. 4 via Ticketmaster, but a limited number of pre-sale tickets will be available beginning Jan. 28 via Johnson's official Web site.

Johnson is gearing up for the Feb. 7 release of the soundtrack to the animated film "Curious George," which features a number of his songs plus appearances by Harper, G. Love and Matt Costa.

He is also about to embark on an extensive international tour, beginning Feb. 22 in Dublin and wrapping April 15 in Chiba, Japan.