Classical metadata formatting is a bit of nightmare. You can't just run it through Picard and expect good results, sadly there's just legwork involved.
For me, I will have this sort of directory structure:
- Johann Sebastian Bach
- St. Matthew Passion
- The Bach Collegium Japan and Masaki Suzuki
- The Vienna Philharmonic and Herbert Karajan
- Goldberg Variations
etc. metadata usually looks like this:
Performer/Album Artist: [Solo Performer Full Name, The [Name] Orchestra and [Conductor] with [Soloist, Concertist]
e.g. The New York Philharmonic and Leonard Bernstein with Van Cliburn
Album: [Composition Name]
e.g. Piano Sonata No. 32 Op. 111
Here Beethoven and Maurizio Pollini are implied from the Artist and Album Artist Fields
Filename: Whatever, just keep it short enough so filesystem isn't mad.
Track Name: Piano Sonata No. 32 Op. 111 - Movement 2 Adagio molto e cantabile
Something like that. Consistency is key. I wish it was less of a pain in the ass but in the absence of recognized standards, you'll be translating things out of German, flipping around Artist/Album Artist, etc.
Foobar2000 and JRiver (Windows) both have good regex tools for standardizing things but like I said it's just tedious. I think it's worth it though.