Music games have become very popular these days and it definitely looks like they won't stop growing in terms of sales anytime soon. This is largely due to the fact that most of these titles feature songs that are very popular with a wide variety of people, who, along with their family or friends, can play these songs together.

The two big companies in the music game industry, Activision, with its Guitar Hero franchise, and Harmonix, with Rock Band, are struggling to profit from cult bands and have both announced that they will release new titles. From Harmonix we will see a completely new game, dedicated to the massively popular Beatles band, which will feature a lot of new things. But, as it has already done with Aerosmith, Activision will release a new Guitar Hero title branded with the legendary hard rock band Metallica.

Although the game, entitled Guitar Hero: Metallica, obviously, promises to bring a complete experience based on one of the most popular rock bands of the last few decades, it will also include songs from other bands, as we reported some time ago. Joining the famed group, bands like Slayer, Alice in Chains or Judas Priest will also be available in this game. However, although these groups have been confirmed, it was definitely a challenge to bring some of them into this future title.

Lars Ulrich, the drummer of the famous hard rock band, has recently spoken with Game Informer about the challenges the team at Activision and his band faced when they tried to bring Slayer into the lineup of bands for this new game. “I'm super psyched we got Slayer in there. Slayer's got to be part of any heavy metal video game. There had been some issues with their lyrics. That gets into a whole slew of stuff like, 'Microsoft won't do it if this lyrical content is in there.' There's all this [nonsense] you have to deal with, but we stood up for Slayer, and we finally got Slayer cleared like a week ago.”

Although sometimes inappropriate lyrics have been a part of rock songs for quite a while, it seems that the option of on-screen lyrics might have really affected some companies. But let's just be happy that the team at Activision didn't give up and managed to bring the popular band onto this future game. Guitar Hero: Metallica has been under development for some time now, but, unfortunately, a concrete launch date hasn't been scheduled.