Christina Aguilera I'm PERFORMING At MJ Tribute Concert

8/11/2011 9:19 AM PDT

Christina Aguilera SIGNS ON for MJ Tribute Show

Christina Aguilera has finally agreed to perform at the Michael Jackson Tribute Concert in Wales in October ... promoters have announced.

Xtina will be joined by Cee Lo, Smokey Robinson, Leona Lewis, Craig David, UK boy band JLS, and Alien Ant Farm -- known for their 2001 cover of MJ's "Smooth Criminal."

Members of the Jackson family will also be performing at the October 8th concert in Cardiff -- including several of his brothers -- but we're guessing that list doesn't include Jermaine or Randy.

According to an executive for Global Live Events, this is just the tip of the iceberg -- "This announcement is just the beginning, we have many more to announce."