From casual listening of “oldies” radio and some music I have from that era (Beatles, Stones. The Who, Motown…) its seems that 1966 titles represent a huge step forward in sound quality and production from 1965 titles…I think the Beatles’ Rubber Soul album (Dec. 1965) may have around been the turning point.
What caused this great leap forward? Did people notice it at the time?
Isn’t that about when mono LP’s bit the dust?
In November, 1965, Dolby Laboratories introduced its A-type noise reduction system, so it’s possible the big improvement was simply getting rid of the sonic gunk from the master tapes.
Stereo LPs overtook mono in the late 60’s as well.
I appreciate there may be specific technological reasons such as Dolby A, but the early 1960s also saw a major change in how records were made: people like Phil Spector and Joe Meek started putting so much more effort into recording, using new effects technologies and much more complicated instrumentation rather than just trying to capture the live sound.
Also they simply spent much longer time trying to create the best possible recording. In contrast, most singles prior to the mid 1960s would be recorded in a couple of hours or a day at most.
Early innovators like Spector were followed by the likes of Brian Wilson who spent months in the studio putting Pet Sounds together, and George Martin and the Beatles who, inspired by Wilson, put an equal amount of effort into their later albums.