Find my Song.

I was just wondering if there can be a better method to find music, songs. Finding music or songs is mainly dependent on the idea of tags. I mean we need to know tag information about the song to find a song.
Also if we have duplicate songs, which are gathered from different sources, it is difficult to find it, until all songs are properly tagged.
Say we have  a song and don't have any of its tag information, how can we retrieve its information.
So I came up with idea of searching music with actual music.

The idea is very simple, we down-sample the music we need to search, and then match the pattern in original file with approximation.
Firstly we would downsample the file so that we get a rough wave of the music, we don't need accuracy cause it would be difficult to match waves exactly when music can be ripped at different sampling rate.
Now after downsampling the music, we reconstruct the wave. Now the music sample we have which we will search in the source file will also be downsampled at the same sampling rate, and the wave will be reconstructed. Now this wave will be approximately matched with the wave of the original file.

If we have a match we know which song this is, else, it doesn't match.

The drawback of this method would be that it actually requires a lot of processing. But we might be able to get way out this. Say we downsample first few seconds and store in the file itself, now when we get a start of a song, we compare this with the data, and if it matches we know that this is the same song.

The idea is very abstract right now, but i am wondering how can i test the same and actually see how feasible this option is.