Bach — Goldberg Variations, Complete

Bach published the Goldbergs in 1741: an aria, thirty variations, then the aria again at the end. The variations do not follow the melody at all — they are built on the bass line and harmonic frame, with every third one a canon at a widening interval. It is a structure of almost mathematical severity that somehow never stops sounding like music, which is why people have spent three centuries arguing about it.

This particular recording is worth choosing on purpose. Kimiko Ishizaka recorded it in 2012 as the Open Goldberg Variations, crowdfunded specifically so that both the performance and the score could be released into the public domain — no copyright, free for anything. Given how much of the classical repertoire is public domain as composition but locked up as recording, that is rarer than it should be. It is also, entirely separately, a very good performance.