I can tell you in my opinion the RB keys are useless unless you know how to read those keys?? With mixed in key you know you can go from a 2A to a 4A etc... I have NO clue with the RB keys. So what I have done is set up mixed in key to have the Key show up before the song so I can see it on the CDJ with have to wait for it to scroll. This is one thing I hope they change in RB. We are all DJ's. But not even the biggest musicians in the world no how to read music and keys. Not sure what they were thinking when they did it that way??? Well.... They weren't thinking!!