The list of artists lined up to honor the late Metal God Ronnie James Dio - solo singer - onetime Black Sabbath and Rainbow frontman is quite impressive.  Rob Halford (Judas Priest), Ian Gillan (Deep Purple), Lemmy Kilmister (Motorhead) and Dave Grohl (Nirvana and Foo Fighters) among others.

Spearheading the project is Dio's widow, Wendy, who was the singer's long time manager up to his untimely death on May 16, 2010, at age 67 after a battle with stomach cancer.

Wendy Dio is taking a hands-off approach and letting the artists pick what songs they want to do, the way they want to do it.

Halford will reportedly cover "Long Live Rock 'N' Roll," the title track to Dio's last record with Rainbow, while Grohl is set to tackle "The Mob Rules" the title cut from the second Sabbath album to feature Dio as it's front man.