A really good place to start. He wrote for almost every genre except opera.
The textbook nature of his music means that everybody who comes after has learned from it.
his well-tempered clavier is literally a textbook you can listen to again and again and hear something new. In Bach, you’ll find every aspect of musicianship: energy, melody, rhythm, harmony instrumentation and form are at their highest peak. his music is like Legos, where all these individual parts fit together with such clarity and precision that you can take any piece by him and play it on any instrumental ensemble, be it steel drums or kazoos, and it will sound just right. Lots of people over the years have recast and orchestrated Bach, mostly his organ pieces, which have lots of color to begin with.
As with all of this musical literature, you don’t have to pay as much attention to this as you would a good book because the Baroque style – being so consistent in dynamic curve and pithy sections – makes good background. A very good accompaniment to housework and dinner parties.
I do mostly recommend deep listening, though. It me helped focus, especially when I got into very difficult modern stuff. the very act of listening to un-amplified music in concert with natural acoustics and overtones can’t be underestimated.
Pro tip: Music from this era in the minor key is often more instantly engaging.