TOD:
It is hard to say exactly what and when, but...
My earliest memory -- my maternal grandfather lived with my parents and me from 1950-54 (my grandmother had died in 1949. My grandfather remarried in 1954) -- and he had furniture in our house, including a console record player/radio. He had a lot of 78 rpm records, and when I was 5 or 6, he showed me how to play them.
I was completely fascinated by his recordings by Les Paul and Mary Ford. "The World is Waiting for the Sunrise" is one I distinctly remember. When he remarried, all his household goods went with him, and all I had was a small plastic-cased record player that played 45s...and all of mine were children's recordings including that awful "Teddy Bears Picnic" record I know I've mentioned here before.
The radio played an important part in my music appreciation for many years. I loved Gale Storm!!
My film music interests began in 1960 with "Exodus", and they evolved over the next few years to become an all-consuming passion.
My classical music interests began, believe it or not, with my hearing part of Elgar's "Enigma Variations" -- the "Nimrod Suite", to be precise -- in the film "Young Winston". While I had several recordings of Strauss Waltzes and a few classical works that I had been exposed to in high school band, it was the discovery of that Elgar composition that lit the classical fires within me. While in the Navy, I was assigned to Vicenza, Italy, to work in the AFRTS radio station. Many wonderful people worked at the installation, especially in theater, and they broadened my interests greatly. My love of opera began there when I found a stereo recording of "Turandot" -- the Joan Sutherland-Luciano Pavarotti recording. That is still the seminal recording of that opera in my estimation, and I have listened to quite a few recordings of it.