Initially audio files didn’t have any other information about their content except name of file itself. The situation changed in 1996, when Eric Kemp invented ID3v1 tags. The idea was to put some more description into audio files. Why not? File contains pure information, after all.
The invention was quickly adopted and became a standard for the most popular audio format – MP3. A bit later came an improvement: Michael Mutschler has taken one byte from comment field and used it to save track number.
In general ID3v1 tags allow to store information about artist, title, album, year, track number, and a small comment. There was no more need to invent tricky filenames (and not every operating system supported long filenames at the time). You could save your albums as “1.mp3”, “2.mp3” etc. and still have a pleasure to read sensible info in your favorite media player. The tags were saved at the end of the file to prevent some older players from playing non-enjoyable splash when opening the file. You see, older players thought it was music too. Information is information.
Well, so far so good. ID3v1 tags had 30 bytes to save artist, title, album info, and comment. 30 letters. Not many.
Could it be more? Why not? The inventor of ID3v1 tags decided that 30 bytes were sufficient. But anybody else could decide otherwise. It is not difficult to invent a new feature. The only difficulty is to make it so good that it will be adopted as a standard.
So, ID3v2 tags finally appeared. It was no improvement of the ID3v1. ID3v2 used completely different approach. And that was the key to success.
First of all, ID3v2 tags were saved at the beginning of the file. Very useful for streaming media. Better still, they could store all information you wanted them to. No limits were set. There were some standard frames, like artist, title, album, year etc., but anybody could define new frames. Some valuable containers were added, for example, for cover art and lyrics. Long titles were no more truncated.
Sounds perfect? Well, it is, to an extent. ID3v2 tags are widely used, and many other file types have got similar containers to store all information related to the file. The structure may differ, but the meaning remains untouched. You get all you want to know about the file in one place. This place is the file itself, and the information is completely independent of filename. More yet, it is in convenient form and allows you to search for some specific entries much more easily than with filenames. Most contemporary media players have nice features based on ID3 tags.
For full control over ID3 tags we recommend mp3Tag.