Preface and general thoughts 
According to Commons:Categories, every media should be located in the following categories or one of its subcats:
- Category:Image sources. This category is not widely used. However, if there are common sources for music related media, subcats and even Category:Music media by source could be useful. In my opinion, it is not really a primary target.
- Category:Copyright statuses. This category is widely used. If there is a music related source with individual coypright status and template, this cat could be of interest.
- Category:Media types. This cat is of great interest and should be taken into account.
- Category:Topics. Since we are a specific subcategory of this cat, we are not to care about its structure. There will be some intersections, but they are not of importance.
- Category:Categories. Here is the main playground for categories. We have to examine the structure in detail and put in our subcats where appropriate.
- Nearly all files should be sorted by genre. This is realised via Category:Musical genres.
- Most files should be sorted by location. This is realised via Category:Music by country, but we need a structure which represents the different types of locations like Halls, Open Air, Studio, and so on. This is not yet realised.
- Many files could be sorted by year. This is realised in Category:Music by year.
Now there are some rather difficult points. Currently, there are trees like Category:Musicians and Category:Musical groups. However, these do not contain media representing musicians or groups, but sort media by musician or group. I'm not quite sure, if we really need categories which exlusively contain pictures of musicians. Same considerations apply for Category:Music venues and Category:Musical instruments.
- Files could be sorted by type. This is not reasonable for images, since most are images, but all other media should be located in a proper category.
Categories which should not contain files or articles directly 
Music by year 
Some of the Music by year categories were created in the "[year] in music" form; I have suggested they be standardized in the form "Music in [year]", with so far positive feedback. Any objections or other thoughts? -- Infrogmation 20:59, 5 October 2007 (UTC)
Music is such a central topic that I highly recommend to have it directly in Category:Topics. Otherwise you need many steps more if you click from root. I have tried to find the topic Category:Jazz from root and it took more very long. --Ingo1968 (talk) 14:40, 27 September 2012 (UTC)
- With more than 2.2 million categories, none is easy to find. For simple names as music, just type category:music or category:jazz in the search box. We don't have to break the categorisation logic too much to improve only marginally on the beginning of a navigation. --Foroa (talk) 15:19, 27 September 2012 (UTC)