Unlike Rock Band, you actually have to know how to play music to do what these guys are doing. Here is another group doing a Christmas concert with iPads: http://www.youtube.com/watch?v=7DJddb73OOQ
Or how about 1 guy putting all the pieces together himself: http://www.youtube.com/watch?v=yYo5dCeBZYA
Garage Band comes free on Apple computers and the same ‘equipment’ would have cost about $20,000 and needed it’s own room when I was a kid. It’s just amazing what you can do these days if you have a musical or creative flare.
Taking this one step further. Have a look at what Eric Whitacre did using technology to connect “individuals alone, together.” http://www.youtube.com/watch?v=zyLX2cke-Lw
Rock band is fun, but making music is definitely beyond Rock Band!