David, I know that you asked Paul the question but as a rabid classical music fan, here is my advice.
The quality of reproduction is not the deciding factor, it's the quality and interest of the performance in classical music which is important. There are any number of recordings of the famous classical pieces and often the best or most interesting performances are terribly recorded. I will give you an example of William Kapell playing Chopin's 2nd piano sonata in the Geelong Town Hall in 1953. It was fortunately recorded on acetate and the sound quality is extremely poor but you forget that as you listen to this inspired performance. The Funeral March 2nd movement is especially powerful when you realize the pianist died in a plane crash a few days later.
https://www.youtube.com/watch?v=Zi5onHLdV1IWhat you need is a guide and one of the best is a subscription to the Gramophone magazine. Each month they review recent releases and you can build up your playlist for the month as you go through the reviews. As you listen you can read the review again and learn from what you are hearing compared to what the reviewer is writing. You may disagree profoundly as I am doing now listening to some Schumann conducted by John Eliot Gardiner. He is a conductor I normally enjoy but this was woeful. The reviewer liked the performance.
I don't have much experience with the other streaming services but Qobuz has most of what I want to listen to and the search mechanism is good.
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