I was going through some of my old LPs for my project comparing vinyl to digital music. In 1973, JBL put out an LP called Sessions where they went through the process of creating an album. It is very interesting and shows how they use multi track recording with both mics and direct instrument feeds. They also go into the many effects used during mastering including EQ, pan pots, and reverb to get some semblance of space, even though artificial. They also go through different levels of the adjustments to get to the final mix. Although it was never released in digital format, there is a YouTube video where someone must have ripped the vinyl to video. The quality is not as good as a direct play from the vinyl, but it is very interesting, nonetheless.
Tom
https://www.youtube.com/watch?v=AJ_XRXnVnN8