No input mixer

This is bold.

No, it is.
I mean, you get some short colored patch cables and start to connect mixer outputs to inputs… until you get bored. Then you start to play on the thing.
Well, noise is easy.
Music, not that easy.

Well, you may start checking Mr. Christian Carrière: http://createdigitalmusic.com/2011/12/no-input-part-fratres-played-on-a-mixer-is-eerily-beautiful/ .
If you can control you mixer at this level, I think it could be a good start.
And, no, you don’t need a $99999 console (see Adam Saikaley: http://www.youtube.com/watch?v=PmtU39OczZU&feature=endscreen&NR=1 ).
And no, you don’t have to be a pianist.

You may also check Mr. Adam Saikaley: http://www.youtube.com/watch?v=SP4rXx6Jhuo&feature=mfu_in_order&list=UL  .
Adam Saikaley on a rack setup: http://www.youtube.com/watch?v=gcmiDzjmeUQ&feature=mfu_in_order&list=UL .

Now, for your home, check this NIM demo with a cheap small format Behringer UB802 mixer: http://www.youtube.com/watch?v=FLVkCmJvXTw .