There’s a reason for this gradual change. Let’s just say that both collectors and engineers entered into a more complex world once stereo technology was introduced to consumers. To play a stereo record, collectors initially needed specialized setups, or they would risk damaging their equipment and records. On the production side, there was a steep learning curve and added expenses for releasing stereo records.

Albums originally released in this purgatory period between 1958 and 1970 – when many albums were produced in both mono and stereo versions, in varying degrees of quality – require some extra consideration from collectors.