Once upon a time, there were some giant companies that, with the failure of the 4-channel battle fresh in mind,
formed an expert group with the mission to invent tomorrow's technology in sound compression. Fortunately, they did.
The format, named MPEG Layer 3 or for short MP3, took advantage of the fact that
our ears are not nearly as good as we generally believe them to be, and thus omitting frequencies that we wouldn't
hear anyway. They also made the format suitable for streaming by letting the sound be represented in small,
individually compressed blocks of audio data. Each block had a header containing some information relevant to the
decoding process. As they ended up with a few bits to much, they used them for some additional information such as
a 'copyright' bit and a 'private' bit.
Since the format had such an outstanding compression and still very good sound quality, it was soon adapted as
the de facto standard for digital music. The lack of possibilities to include textual information in the files was
however disturbingly present. Suddenly, someone (Eric Kemp alias NamkraD, I've been told) had a vision of a
fix-sized 128-byte tag that would reside at the end of the audio file. It would include title, artist, album, year,
genre and a comment field. Someone, possibly the very same someone, implemented this and everyone was happy. Soon
afterwards, Michael Mutschler, the author of MP3ext, extended this
tag, called ID3, to also include which track on the CD the music originated from. He used the last two bytes of the
comment field for this and named his variant ID3 v1.1.
(more information about ID3 and ID3v1.1 can be found here)