“How about all those Rock Band DLC songs I bought on my PlayStation 3?”
That’s a fair question! We’ve always been committed to the idea that Rock Band is a platform, and as such Rock Band 4 will support all your previous DLC purchases at no additional cost! (Be sure to thank our friends at PlayStation, because we couldn’t pull this off without significant work from them!)
http://blog.eu.playstation.com/2015/03/ ... -ps4-year/
New drum kit and guitar hardware, but it supports old PS3 and 360 instruments too.