Ozzy has known West and Laing for over 35 years — Black Sabbath\'s first United States tour was as the opening act for Mountain.

The friendship was renewed in 2005 when Osbourne recorded Mountain\'s Mississippi Queen for his \'Prince of Darkness\' box set, and he got West to play guitar on the track.

Mountain history
Mountain was formed during the Woodstock year of 1969. This New York based foursome consisted of Leslie West on guitars and vocals \"king of vibrato and tone\" formally from The Vagrants. Canadian drummer Corky Laing provided the thunderous heartbeat with his trade cowbell and double bass drumming. Felix Pappalardi, who produced Cream and other acts of that era, was also the bassist and vocalist. Steve Knight filled the holes with with his keyboard textures.

Together these guys made rock history with their albums \'Climbing\' and \'Nantucket Sleighride\'. Mississippi Queen is a classic rock staple to this day. Mountain, still actively, continue touring to sold out shows all over the world.