Nowadays it's easy to almost instantly write off just about any music game coming out. However I will tell you why these 3 games matter.
Now, rockband was good, rockband 2 was better.... and the 3 small spinoffs were pretty ok as well. But Harmonix, ever intent on breaking their own mold, Found a way to further improve the game, keyboard, and REAL GUITAR(don't forget pro drums). Throw in 3 part vocal harmonies, and your whole family, and neighbors will have a hell of a good time playing Bohemian rhapsody. add drop in drop out multiplayer, and a sprinkling of more awesome stuff, and you got what may be the best music game ever!
DJ hero 2
When the first DJ hero game came out me and my brother were both on the fence about it, wondering what to do about it. we didnt buy it.... however we did play it extensively at best buy.( i was hooked instantly.... brandon is just now coming around what with DJ hero 2 out). to me the improvements are readily apparant ( and Deadmou5 looks amazing in the game). Much to my surprise, and personal dismay, We both had fun playing a lady gaga/deadmou5 mix. we suck horribly, but with him on hard and me on expert i still inexplicably win....
guitar hero 6:
Now i could pass this off as just another guitar hero game.... and really..... it just kinda is.... save for one of the best track listings to date, and improved graphics, (and the rather un needed story mode) and rush's 2112!(that's an improvement on it's own) , it shares a lot of paralell songs with rockband.... and kinda expectedly, rockband did it all better
verdict: buy for 2112 and the exclusive megadeth tune.... that's about it
:sidenote: powergig, rise of the six string:
it kinda goes without saying that this game will flop.... they try something different.... but i can say it will not work.... especially for drummers, we need something we can actually hit..... not just swing madly in the air...
that doesnt mean i won't try it. but i know, just like rock revolution, it will flop horribly
one more sidenote.... if you don't know what rock revolution is.... basically.... take a japanese developer, credited with essentially creating music games... .and watch them fuck up BAD