Not that it's not a good program. But they assign several attributes to songs, including genre. At the moment, I only have a few albums, one each by Motorhead, Megadeth, Skid Row and Judas Priest. According to iTunes, Megadeth is metal. OK so far. But then they list Motorhead and Judas Priest as rock. Depending on the album, I suppose both are arguable. But they did also help define the genre, especially Priest. Rob Halford introduced the leather look to metal (rumor has it, because he liked it on the motorcycle Village Person,) and has held the title of "Metal God."
After saying that Judas Priest and Motorhead aren't metal, iTunes goes on to say that Skid Row is. I suppose that I'll have to give iTunes that one, because if Skid Row was never metal, Metallica wouldn't have taken the genre away from them. But it's a little like giving Green Day credit for being punk, grunge, or anything else other than sucky.
I bet Apple likes them, though.