Composers, performers, soloists, conductors
Organising classical portions of your digital music collection requires some thought. The tools and techniques with which digital music is organised is oriented toward popular music forms and most music players do not expose all the information which allow you to navigate classical music. Choosing the best way to organise digital music becomes a compromise between the number of different music players you use, their flexibility and the ways in which you want to navigate classical music.
There are basically two reasons that digital classical music is tough. The first is that the very way in which digital music information is organised, tags, was designed with popular music in mind. The second is that most of the mainstream players do not offer good support for navigating the extra information related to classical music.
The tagging issue is rooted in the fact that mainstream popular music is generally work oriented while classical music is performance oriented. The two principal tags relating to any piece of digital music that digital music players rely on are the 'album' and 'artist' tags. It's generally fairly simple to decide on an album tag for classical or popular music. This will generally be the name of the work. In the case of popular music, this may be "Dark Side Of The Moon", and in classical's "Violin Concerto No. 1 in D major" (variations may include opus number). In classical's case, you are more likely to have duplicates where different performers have performed the same work. Indeed, because classical music is performance oriented and there is much more information to be stored about the performance, if anything there is not enough space to record all information of interest. But it's the artist tag that divides opinion.
According to the ID3v2.3 specification, the artist tag (TPE1) should be:
The 'Lead artist(s)/Lead performer(s)/Soloist(s)/Performing group' is used for the main artist(s).
Applied to classical music, this suggests that one use either a collective name for the performers or a soloist. The very fact that there is this uncertainty is one downside, but much worse is that, given the artist tag is a principal means of navigation for most music players, your music is now organised by soloist or lead performer. In a soley classical library, this may make some sense, but for most music collections the music lover would prefer to navigate by composer, not performer. I know that's the way I would prefer things.
Your music player may be more flexible, and may allow browsing by composer. A separate composer tag exists in all of the major digital music formats, as do tags for performers, accompaniment and conductor. If you do use exclusively music players with good support for the classical music tags, you can go ahead and store composers, performers, soloists and conductors in their applicable tags. However, if not, you may have to commit the cardinal sin of using the artist tag for a purpose it was not defined: composers. That said, at least you will be able to navigate your music effectively.
Another possibility is to adopt a classical work naming scheme, including the performers in it in the 'album' tag. For instance, you may have the work name, followed by soloist, orchestra and then conductor. This has the downside of leading to very long names.
One other thing on composer names: try to make them consistent. Artist name consistency is a rule I'll be adding to bliss in the future. For instance, for J. S. Bach make sure to collect all references to Johann Sebastian Bach, JS Bach and more. This gets more complicated with musical dynasties, like the Bachs!
Thanks to arquera and stevendepolo for the images above.