As promised, the Green Apple Festival has added more artists to their already stellar list for Earth Day 2008 on the National Mall. In addition to Thievery Corporation's DJ set, Umphrey's McGee, Gov't Mule, Toots and the Maytals, Warren Haynes, and a variety of local acts, the festival has just announced the following:

The Roots and Friends featuring Doug E. Fresh, Ne-Yo, Talib Kweli, will.i.am, Chrisette Michele and more.

O.A.R. acoustic

and the National Anthem will be performed by American Idol winner Jordin Sparks.

Speakers for the event are still being confirmed, but stay tuned to the festival site for updated information and a list of other local Earth Day events.

The Green Apple Festival will take place on Sunday April 20th, and is free for all to attend. It is being held on the National Mall in Washington DC as well as simultaneously in various other major cities around the US. Don't miss out on this amazing event!