Cross Purposes is one of the most underrated and least mentioned albums in the entire discography of Black Sabbath. It features one of their prominent singers, Tony Martin, as the band's third official singer and the second to their last albums to feature Martin before the return of Ozzy Osbourne (the band's first and most notable singer). Cross Purposes contains a series of songs range from hard rock to heavy metal. It contains a more progressive album than their previous albums. Cross Purposes indicates the continuous experimentation and innovation Black Sabbath has produced in over two decades.