i came up with an idea of doing a music recognition for my theses but i do not know where to start from. basically this app will be that one plays a song from his PC (for now) and the program will recognize the song and finds the name, author etc of the song.

Thank you very much for your help :)

This is a large and complex project that will require you to have extensive knowledge in multiple areas.

I would start here and follow some of the open software links to see how they did it.