Again personally i never had issues finding classical music on Spotify if that particular performance is available. I might not be a classical music connoisseur but merely a peasant that enjoy's common recordings and yo yo ma but i never had issues.
I've also never had issues searching Spotify using an Opus catalog number, e.g. your example of Bach which seems to work just fine for me... http://i.imgur.com/VGHCcH3.png
They've gotten a little better at exact matches, but in the "BWV 588" example, you still have to scroll past a screenful of the Goldberg Variations. Sure, the Goldberg Variations are great, but that's not what I asked for.
That screenshot also highlights the problem that shitty performances rank highly in the search. Kevin Bowyer will probably play an organ piece with much more skill and subtlety than "Mutant Orchestra" on "Classical Halloween Bach from the Dead", but guess which one ranks higher.
Don't search by a pure opus or a BWV number then if you search Canzona in D + Insert Performance Details you'll find it.
Never had an issue finding what i wanted, i didn't mind to have to scroll and i treat Spotify's search just as i treat Google's search, the secret to finding stuff on Google is to figure out what the 100000 idiots that searched for the same thing before you actually searched for before ending up clicking on what you really want.
The 1st several results will be SEO's then couple of promoted ones then you'll find something that you can actually use, and Spotify isn't any different I'm pretty sure that record companies pay directly or by accepting lower fees in exchange for Spotify to promote their records, so yep Classical Halloween Bach from the Dead might be promoted, or it might be there because more people actually enjoy listening to it just as most people would probably enjoy TSO's version of Mozart's and Beethoven's works with a nice jam more than some dreadful orchestra from the Soviet days of eastern Europe.
Streaming providers aren't the Library of Congress don't expect them to give you exactly what you look for since they assume like any other search engine that you don't know what you are looking for and they also need to make some money on the side, but if you don't give up and are willing to waste 10 seconds you'll find what you want and then well just hit the bookmark button.
P.S.
If you want to listen to a specific performance why are you searching the work and not the "artist"?
For the most part there will be more performances for a given work than all the recordings a single orchestra can record in it's life time. Want to listen to a recording by Sydney's symphony orchestra? Search for Sydney Symphony Orchestra, click it scroll down till you find it not the other way around :)
I've spent a while making a Bach playlist, so yes, I do have these things basically bookmarked by now. But it sounds like you're telling me that search is easy as long as I know exactly what I want to find.
The problem with classical metadata is when you know the work you want to find, and you want a quality performance, but you don't necessarily know:
- What "title" it was given. Titles are neither consistent nor unique. You're telling me with confidence that you can search for "Canzona in D", which is ridiculous, it only finds performances that used that particular mix of English and Italian to title a piece written by a German speaker.
- Whether a particular recommended performance is going to be available on Spotify
- Whether you can click on the "album" to get the rest of the movements, or whether you just found a standalone track
- Whether the "artist" is going to list the composer, the performance group, or one famous performer
So it takes a lot of trial and error. I know I need to do some work to search, but they're not even trying to put the appropriate data in. It's like browsing a bookstore that's sorted by color.
The problem here is that all of Spotify is built around the "title", "artist", and "album" tags, which were originally added to MP3s as a way to catalogue popular music from about 1950 to 2000, and none of which are a consistent way to organize classical music. Classical music is organized by composer, work, movement, arrangement, and a whole lot of performers.
If you get deeper into listening to classical music, you will find that there are choices besides "Bach from the Dead" and "dreadful orchestras from the Soviet days", and you'll also find that the metadata situation is not as rosy as you make it.
I've also never had issues searching Spotify using an Opus catalog number, e.g. your example of Bach which seems to work just fine for me... http://i.imgur.com/VGHCcH3.png