I liked Rock Band somewhat when it was out, but Blitz was my game hands down and got me to download about 100 songs in the course of a year. Luckily, those all transfer over to Rock Band 4, which is due out this October for the Xbox One and Playstation 4.
Due to it being E3, Harmonix recently released a new trailer for their returning music title, showing off freestyle mode that allows the player to simply go wild with it for a short amount of time. It looks pretty great thus far, and you and watch the official trailer down below, showing off the mode in full.
Remember to pre-order as well, as if you do and get it on its October 6th date, you get 30 free songs. There is also a nice little clip of the instruments to check out under this text as well. More E3 2015 coverage headed your way, so keep watching.