Since Edison's invention of the phonograph, humanity has been trying to improve the quality and lifelikeness of the recording of voices and musical instruments. I was in a thrift store the other day and noticed this record:
On the back was a bit of a lesson on the spectrum of sound frequencies, as well as the demo's song list.
There's no date on the demonstrator, but I would think late 1950s/early 1960s. By the mid sixties, stereo 331/3 records--LPs, short for Long Playing--were the norm.
This cover story in Popular Science in 1985 heralded the next significant move in sound recording and reproduction--the digital age. This was the Compact Disc and digitally recorded music's time of introduction and it was a significant move. Other technologies had come along side the LP--8 track tapes and cassette tapes--with some improvement in sound and the introduction of portability but no significant change in the way recorded music was made.
Now, the CD is said to be endangered, with sales down every year. The digital revolution continues with downloads storing music in bytes and bits.
And so it goes.