Personally, I would be interested in how a game like this would be handled, since the only other commercial Christian rock rhythm game I can think of was Guitar Praise, and that just had re-recorded guitar lines being played over an MP3 of the song and didn't use stems. However, I severely doubt a game like this would work for several reasons. Most of this is the audience limitation. Fans of The Beatles (which there are a lot of) would buy The Beatles: Rock Band. Content conscious families and fans of Lego toys and games would buy Lego Rock Band. But how many people are there that are fans of specifically Christian-themed rock music? Not too many. The game would not have enough public interest in a lot of the places where Rock Band was/is popular, which is not a very good thing for a company who wants people to buy their games. And even if it was a Rock Band title, it would probably not be promoted a whole lot since most, if not all, major retailers are very secularized places. And finally, wouldn't Harmonix avoid making it anyway since they are not a religious company as well?