Ozzy Osbourne vs Black Sabbath

Ozzy Osbourne is suing Tony Iommi, former band mate, over the rights to Black Sabbath. Iommi is claiming sole ownership of the Black Sabbath name and Ozzy believes he is entitled to 50%. Ozzy claims it is his vocals during his time with Black Sabbath that makes the name so valuable. I don’t know who should own the rights to the name, but the only reason I ever listened to Black Sabbath was because Ozzy was singing.