All true, but don't leave out the growth of MONEY. Yes there has always been money in music, but with the advent of the Beatles, Rolling Stones, Dave Clark Five, and especially The Beach Boys, the younger generation got into music in a big way. These kids also were not shy about spending money. I know. I was one of them.
Here's the deal. My parents grew up in the depression and didn't spend what they didn't have to spend. That meant that music was enjoyed in the car on the AM radio that came with the car. Maybe there was a radio in the kitchen that played Sinatra or Tony Bennett. We had an Uncle that was childless and had some extra money and he had a "Hi Fi" in his living room. It was a nice piece of furniture. He bragged that he had "more than fifty albums" in his library. (I found out later that most were 78's, and not LP's). By the time I was 17, my rig left him in the dust. My friends rigs left mine in the dust. I had maybe 130 albums and my friends complained that my selection was too limited.
The point being that by 1970 money was ROLLING into the record companies in amounts that could only be dreamed of before. The record companies didn't mind spending a few bucks for state of the art recording equipment. The equipment makers noticed and soon last years state of the art was second rate and new stuff was needed.
All this was because of the musical groups that caught the attention of the baby boomers at a time when they could spend money that the older generation couldn't or wouldn't spend. The Beatles had more to do with this phenomena than simply the march of time.
And on the subject of the Beatles, this is purportedly the recording equipment in use at Abbey Road during their early years:
This is not an area of my expertise, but I daresay a typical home computer equipped with today's recording software applications rivals what was available to George Martin at the time.
Great observation, and quite true.
I became a music buyer in 1966 at the age of 13. I may have been spending my parents' money, but those few dollars went toward building the burgeoning rock music industry.
Over the course of my teens and my young adulthood, I put thousands of dollars into that segment of the economy. And my spending was modest compared to what many of my peers spent.
The cumulative effect of all that money flowing in, was revolutionary, in historic terms. Never had artists, and everyone else in the music business, enjoyed such enormous incomes.
You're right on target. All that money (and natural competition among artists) encouraged an explosion in recording technology advancements.