Why recordings made before 1965 sound better.

There are many factors entering into the possible answer to the question, "Why do recordings made before 1965 sound better (than, I assume, those made in more recent years)?"

I’ll add my guess to the mix: At that time the electrical grid we relied on was much simpler and less cluttered with appliance-generated noise than there is now - there was no digital hash in the atmosphere or entering our power lines - thus the idea that we needed power-conditioning hadn’t yet entered anyone’s mind (to my knowledge anyway) as an issue to contend with when making recordings. Besides, everything audio was purely analog, so there was no extraneous digital noise being generated. Recordings were pressed onto vinyl discs and/or magnetic-tape reels, and there was simply NO digital processing of any kind anywhere in the recording chain.

1965 was simply a less electrically-polluted era, resulting in purer recordings (when they were done conscientiously, with scrupulous attention to detail at every step in the recording process).

I didn’t read every word above, but I don’t think anyone mentioned the proliferation of digital reverb. I worked in the recording industry and there used to be 1 reverb - a plate reverb kept in a separate room away from vibration. That was it. You either used it in various amounts or not. When the digital reverb era hit, we all went crazy, putting different reverbs on each instrument to get them to sound their best in isolation, not realizing that we were putting every instrument in a different acoustic space by using a different reverb. That sound became the norm throughout the 80’s and nobody ever seemed to realize the fact because the reverbs sounded so great. But we lost the humanity of the music that the older recordings made with the 1 reverb often had.

I never understood why multi generation mix downs were accepted as means to an end without any consideration of downgrading quality.

Consideration was given to generational loss, but it was balanced against the extra freedom allowed to the artists/producers/engineers by the technology.  Here's a link to how Queen's "Bohemian Rhapsody" was recorded.  In practice this type of music can only be created one track at a time and then mixed into the final song.

Just listening to a monophonic recording of violin and piano from 1951, on Idagio. The openness and air around the instruments is more pronounced than on many stereo recordings made of the same forces after 1965.

They don't sound better to me, because I don't like most music recorded before 1965! 😁