What is a Genre?
Simply, a genre is a way to classify something into groups. While this may not be quite a dictionary definition, it's certainly appropriate for my purposes and it fits the common usage in the areas I am likely to use it for. (that is to say, Genres/Music and Genres/Movies
 What is the problem then?
What I want to do is to organise a method by which music (or movies, or anything) can be divided into genres in a manner better than current methods. Some specific goals are:
- Usable to computers and humans alike
Before going any further, I should say that I doubt any single set of genres will suffice for everyone. It's simply too subjective an issue. What I aim for is a framework in which genres reside. The actual genres chosen by a Metal music fan are unlikely to be the genres chosen by a Country&Western fan. But if the same framework is used, then there hopefully would exist a level of interoperability.
Many existing genre classification methods fall into one of two types:
- A small number of "broad" genres. (eg: CDDBp as used by cddb.com and freedb.org or JJJgenres)
- A large number of "trying-to-be-comprehensive" list of genres. (eg, mp3 id3 tags or CDDB2)
Problems with these methods?
- Both types assume that the genre is a singleton attribute. The song or movie is given exclusively to one genre only.
- There is no differntiation between Styles, Topic and Mood. In a small list, only style tends to be covered. In a comprehensive list, it ends up trying to cover every possible permutation of style, topic and mood!
 My plan
First, the piece in question can be part of multiple genres. eg:
- A song like The Beatles' "Helter Skelter" doesn't have to choose between styles of "pop", "rock", "grunge", "heavy", "alternative" (or more). It can be in some or all of them according to your taste.
- "Back to the Future Part III" fits in both "sci-fi" and "western", and probably "parody" too. It can be in all of them!
note: imdb.com already implements this point with regard to their movie genres. Their genre list isn't too bad either. This paper is more applicable to try and change assumptions in music genrefication.
Secondly, genres for metadata related to the music or movie itself are generated from the known genre. for example, the Genre given to an album or artist would be derived from the genres for the songs on the given album or artist. Similarly with movies for actors, directors, producers and studios.
(note that in implementation, we might choose to store these metagenres in preference to direct genres. (why store "soundtrack" for every track on Star Wars, when you can just store it once for the album? ...or probably even just once for the composer! ;) In this way, the song can be seen to inherit the genre from the parent album or artist (with music) or actor, director, producer, studio (in the case of a movie) ... but strictly speaking, only the work itself as a real genre! Everything else is derived!
So, the big question is:
 How do we choose the genres to use??
Answer: Any way you want. But here is the general selection criteria:
- Diverse in scope - between them we should cover *everything*
- eg, the CDDBp genre list is poor, in that the whole "dance" genre is not represented at all.
- Broad in coverage - no single top-level genre should focus on any specific genre too well.
- eg, "dance" is a broad genre. "Acid House" is too defined.
- comprehensive in partnership with each other, with minimal redundancy/overlap.
- ie, we can generate alot of fine granularity through the intersection of genres. Thus, genres should be chosen to intersect well. eg, "Rock" and "Classical" would intersect well. "Classical" and "Instrumental" would not, having a too-high level of overlap.
- atomic - genres have no precedence or parentage to each other.
- eg, "Rock" and "Classical" ... not "Classical Rock" or "Rock/Classical". The intersection of Classical and Rock is just that. an intersection. No precedence. (Nemo says "too much set theory showing through?)
Also, in addition to these, consider the following...
- sub-genres are allowed, and these are specifically tied to their parent genre.
- eg, "prank", "satire" and "skit" might be subgenres of "comedy"
- Allow seperate and independant genre-lists for each of "style", "content", "topic", "mood" and so on. The list within each would be independant, and follow all guidelines above.
Please refer to the subpages for the actual genrelists for music and movies...:
The long term idea here would be that there is a fairly small, stable list of top-level genres, and it should provide an "adequate" set of classifications. A devotee of a specific genre can use/develop subgenres as needed. A mix of two different collections though should not result in a clash of genre systems :)