In Rock Band 4, you're going to undertake a deeper and more meaningful experience than any music game has sent you on before.
What's it really like to be in a rock 'n' roll band? How do your decisions affect your rise to fame (or lackthereof)? What kinds of fans do you have, and how do their reactions affect what you do? What risks do you take and which ones do you deem "not worth it?" What about the relationships between the band members?
Rock Band 4 aims to incorporate all of these things and much more to create a choose-your-own-adventure style RPG. Sure, if you're in the mood to jump in and just play some tunes, you'll always be able to do that. However, if you want something more interesting and fulfilling, something deeper, then the story campaign sounds like it's going to be just the thing.
According to IGN, you start out as a small hometown band, but where you go from there is up to you. You could become the biggest band in the world or you could become a lesser-known (but still successful) band with a more passionate following.
Perfect example: At various points in the game, you'll be presented with the opportunity to sign on with corporate sponsors. You get a ton of money that you can spend on better gear, but it comes at the price of having to give a spiel for your sponsor at the beginning of every concert. Don't expect the crowd to be feeling your commercial — and that has an actual effect on gameplay because it lowers your crowd approval score before you play a single song. So, you have to play your heart out and make no mistakes to make them forget about the sponsorship thing.
On the flip side, you could deny corporate sponsors and stick to your artistic integrity. Expect the game to respond to this as well, meaning you'll generate less income by remaining an indie. So, you'll have a lot less money for upgrading gear. Yet, at the same time, your crowd approvals will start each gig with a higher handicap and the fans will pretty much dig whatever you do.
That's just one example. Rock Band 4 is throwing plenty of twists that make the game much more challenging and realistic. You might take a gig, only to arrive at the venue and find out that this particular crowd isn't a fan of your style of music. So, winning them over will be seriously hard. Conversely, you might play a gig for a crowd full of "super fans," which can lead to some tricky social navigation situations.
It's all a game of risks, weighing your options and making careful decisions. Also, of course, rocking out to the best of your ability is a huge part of it. There's even an in-game map that will tally up your fans by location. The more fans you get in a specific place, the more likely you are to unlock special surprises.
Rock Band 4 is expected to hit PlayStation 4 and Xbox One by Christmas 2015.