It happens all too often; our favorite band comes apart at the seams due to tension, creative differences, or one of many other reasons. It's always disappointing to think that you may never be able to see these groups perform together again, however, these situations are not always hopeless. Just as often, bands will reunite and continue to play together, much to the delight of fans. But what is it that causes them to split in the first place? This is the real reason these bands reunited after a big break up.