Rock Band 4 is fun. It doesn’t move the franchise forward too far, but rather simply brings a patented formula to the new generation of consoles (don't worry, that's a good thing). Unfortunately, one of the things that it didn’t bring to the new generation of consoles is the incredible lineup of songs included on the discs of the first three games... yet.
In a new post on the official Harmonix Blog, the developer has revealed that they are hard at work on allowing players to export their Rock Band 3 library into Rock Band 4. The details are a bit complicated as there are different situations in play for all of the various Rock Band titles. Basically, what is coming as soon as December is the ability to export your Rock Band 3 library (with a few exceptions as a result of licensing issues) into your new game. This will include any songs that you may have imported into that game from earlier titles. Some Rock Band games no longer offer the ability to export songs to later games, while others do. As long as you have kept up to date with the process, you should be fine.
When it launches, the Rock Band 3 export will cost players $14.99. In order to be eligible for the process, you have to have your copy of the game handy as Harmonix will be electronically verifying your ownership. That, in itself, could cause an issue for some players as Harmonix’s ability to sell Rock Band 3, both physically and digitally, will come to an end on 10/31/2015. That gives you roughly a week to find yourself a new copy.
Things are still a little cloudy right now in terms of the process and the details, but they should clear up as we move closer to the deployment of the export ability. Until then, check out the image below for some clarification regarding which songs / games can and will work as well as for the answers to a few common questions.