Alphabetically. The exception is that the storage space starts with some of those purpose built free standing CD racks, which I was given by a friend and which are useful but won’t take double CDs or certain thick digipacks. Those CDs that come in just a thin sleeve instead of a case DO fit, but look ridiculous sitting in the rack and they are wasting space. Hence non-standard CD sizes go further down in the collection, in the part that is just stacked side by side on the bookshelf.
Strictly speaking, then, my collection is ordered first by type of case, then by artist name, then by release name. So if I am searching for Anathema, i have to remember that A Natural Disaster and We’re Here Because We’re Here are in the rack under ‘A’, but Weather Systems is in the bookshelf because it’s a thick digipack that won’t fit in the rack.
“Alphabetical order” is a simple concept that actually hides a myriad of potential issues. Obviously I follow the usual practice of ordering by artist surname. Someone who was not of European cultural background might have trouble figuring out why Van Halen was not next to Van Morrison (if I had any Van Halen). Likewise Elton John and Jethro Tull both get filed under ‘J’. “Elton John” is a person’s name. Although Jethro Tull was a real person, it’s not the name of the performer; there is no Mr Tull playing on the record. The thing is, though, that it requires knowledge about the artist. This is not a problem for me because it’s my collection and I know why everything is where it is, but it’s an issue I would have to address if I wanted to run a music shop. Where would I file Alice Cooper? “Alice Cooper” was originally the name of a band, not a person, so should go under ‘A’. At a certain point though the lead singer changed his name to Alice Cooper and recorded as a solo artist, so that definitely goes under ‘C’. Splitting Alice Cooper releases into two sections seems ridiculous and would require that a novice buyer were able to distinguish between the early Alice Cooper band releases and the solo releases.
Classical releases, of course, get filed by name of the composer, mainly because I usually can’t remember who the player or the orchestra is, I just know I want to listen to Beethoven’s Sixth. This could conceivably create issues, because it’s not unusual for classical releases to contain works by different composers; for example, Debussy and Ravel often get grouped together on a release. In my case they go under ‘D’ because Debussy is my primary reason for owning the disc.
Filing by genre just would not work for me, because I have a number of CDs where I would have to make awkward decisions about classification. It annoys me that in record shops I see porcupine tree in the “Heavy metal” section, because only a very small fraction of their work could be described as heavy or metal; and I would not normally browse that section of the store because I have little interest in acts like Black sabbath, Metallica or Megadeth.
Ultimately, the best filing system for you is the one that owrks for you,