MR !7493 has been merged, so I'm marking this one as ready. Whilst false positives are theoretically possible, it should be unlikely. Short of implementing more sophisticated probing, I think this is the best I can do. I've ensured the MP3 checks come last, so it won't be possible for false positives to occurs with the prior formats. And although ID3 tags can appear in other formats, in practice it seems they are almost exclusively used in the MP3 format.