Quote by qwave
Even if you have to hands, you can do nice live music. I saw Klaus Schulze playing a CS80 with two hands. And no backing tape. Just playing a single sound. I still got the recording from this. This was real live. But then he and Rainer Bloss started to play some "Ampsy" tracks with just some sound effects being live.
And by the way:
there thousends of profesional and amateur piano players doing concerts with two hands.

Yep but I mean this is also possible with software and a midi-keyboard attached to an pc

I still not see the difference between hardware or software.