Audio Pitch Tracer - Links
Audio to midi transcription - live pitch detection
Audio to midi transcription
The Audio Pitch Tracer is able to capture and transcribe minute nuances of pitch and is therefore best for accurate pitch transcription of solo lines, for instance for bird song or microtonal music.
If what you want to do is to transcribe twelve tone music - particularly polyphonic music - then there are other tools that will be better suited to your aims.
Here are some of the other audio to midi transcription tools available. If you know of others let me know and I'll add them to the list.
WIDI Recognition System
Live pitch detection
If what you want to do is to detect the pitch of the notes you play while you are playing, using software, try the free Shakuhachi tuner which also works with other instruments as well and shows the fingering as well for some wind instruments, with a big dial to show how much each note is sharp or flat in cents compared with concert pitch.
This is an area where there are many hardware and software tools available.
Tune Smithy has live pitch detection too, but it is work in progress - you can find it if you go to the Tuner window (Ctrl + 62). I plan to do more work on it at some point to see if I can improve it. Not recommended at present.