i will add that i got melodyne ages ago with the intention of using it for such things- it definitely does what it says it will do, just note that the translation to midi may be messy in terms of where it detects pitch, and may need some editing, like quantizing, in order for it to sound right, but the tools are easy and straightforward to use. melodyne also has a trial but i dont recall what its limits were. i bought the full version because i recall i couldnt use certain functions i needed in the trial so, just a heads up if you want to use it.