you might want to take a look at the Shazam song classification system, which essentially does a 'brute force' search like the one you sketched out, except with

you might want to take a look at the Shazam song classification system, which essentially does a 'brute force' search like the one you sketched out, except with a lot of cleverness to make it run super-fast research paper: http://www.ee.columbia.edu/~dpwe/papers/Wang03-shazam.pdf http://www.ee.columbia.edu/~dpwe/papers/Wang03-shazam.pdf blog entry summarizing paper: http://laplacian.wordpress.com/2009/01/10/how-shazam-works/ http://laplacian.wordpress.com/2009/01/10/how-shazam-works/