does that even exist? if it does i would like a link to one (: thanks!!

i also need a good website to download anime midi files for synthesia

Hi, my english is very limited, but i'll try to respond you.

There exist wav to midi converters,but they can only transcribe few instrument (as piano, violin, flute, etc). Furthermore, the quality is very bad (the rythms are not respected and all the notes aren't). Why? This is because .mp3, .wav and .midi formats are very differents from each other.
1) Mp3 files are compressed sound formats, wich are causing a significant loss of sound quality, to an extent acceptable to the human ear.
2) Wav files are sound formats wich contain informations on the acoustic wave
3) Midi files are very différents of these two. They contain the information to send to the computer to generate the sound.

The two first are thus succession of 0 and 1 to generate a acoustic wave, the 3th "speak" with the computer and he say how much and what instruments play, with what nuance, etc.

I hope i have said nothing wrong and that i could make myself understood.

For more information : http://www.myriad-online.com/en/sharedxp/audiomidi/audiomidi.htm

Myut-echhi is largely right, it's really hard to automatically convert sound data to note data.

It hasn't stopped people from trying though. It's one of the holy grails of music software design.

I have messed around a bit with one such program called Widi. It can be helpful but usable results do require some human help.
http://widisoft.com/