What does 'as-dur' mean in classical music?

I was trying to find Chopin’s Aeolean Harp and as to not get buried in wind harp sounds I added the ‘as dur’ as I know that was part of the title. Lo and behold there are other songs with ‘as-dur’ in the title. I think it means the song is in A flat major but I’m not sure and if that is true why would A flat major have a special term in the title?

It’s the German word for “major”. “Moll” is the word for minor.

G-Dur would be G Major. B moll would be B minor, etc.

As for why it’s in the title…I dunno. Helps the musicians get the key signature right off the bat i guess.

If you’re looking for the sheet music go to https://imslp.org/wiki/Main_Page

then does the ‘s’ in As represent the flat?

Yes. Here’s a Wikipedia article with translations in German and many other languages

I don’t listen to a ton of classical music, but this seems to be a common practice within the genre. Classical European composers tended not to give individual pieces a unique “name” like we would think of a modern pop song, but rather the “title” was simply a description of what it was. Mozart wrote dozens of preludes and fugues, and many ended up with the same “title.” He has four different pieces titled “Prelude and Fugue in A minor.”

When I think of preludes and fugues, I think of Johann Sebastian Bach’s Well-Tempered Clavier, two sets of preludes and fugues which each have one prelude and fugue in each possible key. In that particular case, specifying the key definitely does help to identify which particular one you mean.

But, to my layman’s ears, knowing the key that a piece of music was written in doesn’t help me much.