I can second this. I’ve been fairly impressed with Idagio in the years I’ve been using it. My only real gripe with it is that it used to be much easier to glance through a composer’s works by genre when looking at the composer’s page. Now that feature is buried a couple of menus down. Otherwise, the audio quality is good for a streaming service, and the catalog is extensive.

(At one point they were testing a feature where you could compare recordings of the same piece. It would effectively allow you to switch between pieces at the exact same moment in the particular passage you were listening to. It was great, and I’m sad they never rolled it out. That feature alone would have made the app worth the monthly subscription.)