Almost everyone in those days had a musical instrument. If you think of how many people today have cell phones and computers, that’s how many people had instruments and how popular music was then.
Why was it so, and why did it stop being so? Was it the easy access to recordings and radio that reduced the urge to buy and play your own music? That people went from being creators to consumers of music?
One reason for everyone having musical instruments might have been the great music from the ‘40s. Also some parents may have passed it on to their kids. I started playing when I was 12 and picked up two instruments. Later, in college my housemate could not believe that I didn’t play the guitar. I did brass instruments. Most of my friends played as well.
Late in life now in my dotage I have picked up the guitar.Not much talent but it’s a pastime and I can still read music. :-)
I have passed it on to my children both play piano and my daughter plays three instruments.