I used to have a light program on my PC that would let you record a short audio file and would display useful information such as note length and tone. It was an extremely helpful tool for experimenting and doodling. The thing is, I don't have access to it anymore, I forgot the name and I can't find it. Anyone know what I'm talking about?
This sounds like an audio to midi converter. By analysing the audio file, you can retrieve pitch and duration information which coincidentally is what you require to generate midi note-on and note-off messages.
ableton has a drag n drop feature that allows you to place a wave or mp3 in a midi track and get kind've interpretation of what the melody and harmony is, though you may have to use your sensibilies to extract the parts you want