@
AnnieWalker
I use
quodlibet for my classical music collection:
https://code.google.com/p/quodlibet/
Its main advantages are full support for custom tags and very powerful searching. This allows you to tag classical music appropriately: 'work', 'movement', 'composer', 'conductor' etc. etc., (as the tags are customisable there's really no limit here: for example, I also have my music tagged by musical era, e.g. 'Romantic', and musical culture, e.g. 'French'). You can then search your collection based on those tags. So I can bring up, for example, all the French music of the Romantic era conducted by von Karajan.
It represents a complete end to all those: "should I put the performer or composer in the 'artist' tag" type questions.