Audio convert into midi. What’s the differences between fiddle~ fzero~ sigmund~ ? – MaxMSP Forum

Pitchtracking is the process of, well, tracking (detecting) the pitch (note, fondamental frequency) of an incoming signal. [fiddle~], [fzero~], [sigmund~], among other (like [retune~] or some custom gen~ pacthers) can serve that purpose.
But this is apparently not what you want to achieve. What you want is to convert transients with short attack into note events, and mapping the volume/strenght/loudness of these transients into the note pitch.
For that purpose, Source audio’s example seems like a good starting point (among maaaaany others).