Default Numbers in Music

[Spotted Horses]

The only pieces that I mentally identify by their opus number alone are the Beethoven String Quartets, especially the late Beethoven Quartets, Op 127, 130, 131, 132, 135. I associate the others with opus number because they are dominated by sets, Op 18 and Op 59. I would have to remind myself the Op 127 is No 12, that Op 59, No 2 is No 8, etc. But I in a conversation (and this is the only place I have conversations about music) I would never refer to "Op 127" without being explicit that I am talking about a Beethoven String Quartet.

I don't mentally think of other works by Beethoven or other composers primarily by opus number.

[Jo498]

I think in opus numbers for Beethoven's quartets, piano sonatas, violin sonatas, trios; cello sonatas either way because they are only 5 but more in opus numbers. Symphonies and concerti in plain numbers but of course I'd know their opus numbers.

In the case of Mozart I remember most pieces by K number, except symphonies, and in cases I don't know the K number I wouldn't know the other number either.

in the case of Schubert I remember the piano sonatas (if I remember them at all) by D number but not the symphonies and I know few D numbers besides the piano sonatas and most famous pieces.

I know very few HWV numbers and not many BWV numbers because the instrumental pieces are usually "naturally grouped" or referred to by keys/titles.