As of today, all the MP3 files are tagged using the same 10 genres as Magnatune uses.
Previously, we tried our best to label music using the ID3 genre which seemed most appropriate.
However, we ran into problems all the time, as the available ID3 genres were defined years ago by Winamp, aren't the most consistent, and there are only 80 of them, with odd choices made.
For example, there are ID3 Genres for "Sound Clip", "Pranks", "Dream", "Bass" and "Trailer", but none for "Electro Rock" or "World", which are two main genres at Magnatune. To work around this in the past, we've identified our World music albums using the ID3 tag "Ethnic", but that doesn't seem all that great a compromise.
Sometimes, where the ID3 tags seemed more nuanced than our "main ten genres" we would assign that genre to the mp3, so some MP3s from us might be labelled "Classic Rock" or "Death Metal". However, when this was all loaded into iTunes or an iPod, there were too many genres too look at, and they were too inconsistently applied.
So... as of now all the MP3 files at Magnatune are assigned the same top level genre that you'll find them in at Magnatune. On my iPod, this makes for a much cleaner organization of our music, and I hope you'll agree.
Thankfully, 8 of our main genres can be found (albeit with slightly different spelling) in the ID3 Genre list, and these are:
10 new age
40 alternative rock
79 hard rock
two of our main genres (World and Electro Rock) aren't available in the ID3 genre list, and so are assigned custom "other" tags, using the ID3v2 standard. That should work fine with iTunes, Winamp, and any modern mp3 player.
However, some mp3 players that only support older style id3 tags might see "Pop" instead of "Eletro Rock" and "Ethnic" instead of "World".
In case you're curious, below is a table of the 80 genres built into the MP3 id3 genre standard. Extensions are possible by using an "other" genre, which works with newer mp3 players (iTunes/Winamp) that support that, which is what we've used for World and Electro Rock.
The standard 80 genres that are part of the ID3v1 standard:
|1||'Classic Rock'||21||'Ska'||41||'Bass'||61||'Christian Rap'|
|6||'Grunge'||26||'Ambient'||46||'Instrumental Pop'||66||'New Wave'|
|18||'Techno'||38||'Gospel'||58||'Cult'||78||'Rock & Roll'|