New Software Idea

Have you ever noticed that some songs belong both to an album and to a compilation (like if you have Let it be and The Blue Album, both by the Beatles)? Noticing this I thought that next-gen music management and playback programs should treat album info as a tag, so that you can tag a song with multiple album names. In this way you could be able to find songs searching in each and all of the albums in which they were published, just like if you had the real CDs.