The one hundred and thirty-first classical recording: #107 Johann Sebastian Bach - The Well-Tempered Clavier
This covers book one, for anyone still following along, based on the given recording and general naming mentioned in the book.
One of the biggest obstacles to overcome sometimes is the unfamiliarity with an instrument or sound. In contemporary music, electric guitars had that effect back in the day, auto tune sounds off to me sometimes and I certainly struggle a bit with more modern music these days even if it grows on me. That same effect goes the other way as well and the sound of a harpsichord is not one that I'm used to. It's a sound that I think I've mostly heard in a larger group, where it mixes in with other instruments, but on its own it has a metal sound that doesn't sit well with a modern ear that's used to a richer sound from modern pianos and such.
Once past that, you get a musically inventive set of works, each a prelude and fugue. While perhaps not always as overly complex as later composers, there's enough layered in each that it shows the skill involved in them. They're abstract enough that they won't hit any direct emotions or tell you their stories, but they manage to get you in their mindset all the same - often a bit sombre, a bit dark, with some making good use of their minor keys.
The biggest downside of listening to the work like this is probably that it's not made to be consumed like one long work. Two hours is a long time and while the variety is there, it's not enough to sustain an active listening experience.