Don't mean to hijack thread but are these the same 2 kids (2 cellos) that were on America's got Talent a few years ago?
 
Jim
 

Basseman
Now I've tried 5 different Audio to Midi Programs including Melodyne! 
But they are all writing nonsense.

Sorry, noob here ;)
I just want to understand what other think is nonsense...
The following is the result from Melodyne "played" by TTS-1:
http://www.fileconvoy.com/dfl.php?id=gf69470f23678bbaa999784520599b0ede9c3dcdc6
No editing, no Melodyne tuning (note separation is set too hi, so many ghosts, my computer can handle just several measures per RFX but still slow) and TTS is not the best piano VSTi. I guess real Melodyne users can get much better result.
 

jimkleban
Don't mean to hijack thread but are these the same 2 kids (2 cellos) that were on America's got Talent a few years ago?
 
Jim

I had to research that, and believe they are different (two brothers 14&16 in 2014, and seem to go by the name "Emil and Dariel"), but very similar material. Even now they are most likely 15&17. I think these are the two you are referencing based on a cursory dig - 14&16 and an act in Las Vegas!
 

Back to the OP, this is Celemony's tutorial on using Melodyne with guitars. The overtone/signal processing concerns are universal to its algorithm. I believe this is a Melodyne 2 tutorial, but is the same principle for the "note confusion" comments.