all 5 Beethoven Piano Concertos, Beethoven and Mozart Piano Sonatas, anything Debussy.....particularly "Images". Haydn string quartets, Segovia guitar recordings. John Tavner (The Protecting Veil and others).
that’s just a small sampling of non vocal recs. if you stream Tidal or Quboz i’d recommend just spending time deep diving into composers and artists and just trying things, building play lists. and as you expand your knowledge and comfort zone you will be more comfortable reading to a wider variety and intensity of classical music. for instance i have a few complete Beethoven and Mahler symphony recordings on my hard drive and will sometimes just allow it it play through and it's a great reading companion. lot's of big music but it's familiar and comfortable for me at this point for reading.
i read a lot to classical music and can relate to your question. of course, even mellow classical can be compelling and draw you in.
