My parents didn’t listen to much music, but my siblings grew up in the swing era and early 50s rock and roll. I gravitated to r&r because of the backbeat, having been fascinated with rhythms since I was a wee bairn. Progressed through the 60s and had a brief flirtation with folk-rock, Dylan, et al, along with some of the more mainstream/crossover 60s jazz scene with Brubeck and Getz. Continued with rock and salsa rhythms and then began getting more interested in bop and post-bop jazz, and world music, such as the Malian sound, Afro-Cuban, and Brazilian samba. I liked a lot of the older C&W stuff, but never really got past Johnny Cash.
My parents’ musical tastes were abysmal - mom was into stuff like John Denver, Anne Murray, Loggins & Messina, Don MacLean; dad was into horrible classic rock: Hot Tuna, Canned Heat, like that - and I was the oldest child, so I had to find my own way. I think I probably owe most of my musical tastes to Creem magazine, which I read all through my formative years in the '80s.
Taste: 1920s to 40s era pop and jazz.
Circumstances: Precociousness plus social withdrawal.
Some of it was from my parents, grandparents and aunts/uncles, between them they introduced me to Dolly Parton, Elvis, ZZ Top, Culture Club, Madonna, The Beatles, Michael Jackson, Kate Bush… actually now that I think of it they really introduced me to a lot.
I liked - and continue to like - current chart music, so there’s that as well.
Because my goal is to have and enjoy a wide range of music in my collection, and failing that at least be knowledgable about music I don’t like, when I was about 13 I started making efforts to discover music that was acclaimed/“important”, but that I wasn’t familiar with yet (discovering The Beatles was part of this too). I still do that by investigating such artists and buying a hits collection or classic album. Hopefully I’ll never reach a point where I look at my CD wall and say “well, this is it” - I want my journey of taste acquisition to last for as long as possible!
Hard to say. My musical tastes didn’t match any of my peers until I got to college. My parents listen to mostly 60’s music, my family listen to country, and my friends were metalheads. My tastes usually revolve around indie rock.
I suppose I could trace the genesis of my tastes to watching anime on Cartoon Network back in middle school. I discovered TMBG from a music video about Dragon Ball Z set to “Particle Man.” I also started liking techno (or at least the techno soundtrack to Toonami), which led me to The Postal Service, which led to Death Cab for Cutie, which led to a whole mess of other bands.
My father is very musical (he writes and sings) so I was raised on a steady diet of Indian classical (instrumental and vocal) as well as the “classic” era of Indian film music. My family’s favourite road trip song was Ek Chatur Naar from Padosan for instance…my sister and I used to screech one part from the back while my parents took the lead from the front! My dad is a bit hardline about not listening to most film music made after some cutoff date that he came up with in his mind. Anyway, he has thousands of very rare recordings and my earliest memories of music involves dancing around to Asha Bhosle and Lata Mangeshkar. My father worships them.
I grew up in the 80s and 90s, so in addition to all the Indian stuff I (had to) listen to, I started expanding into pop, then classic rock and finally alternative. I can also listen to western classical for hours at a time, but I don’t search it out.
The legacy of the Indian music upbringing is that I have to be able to determine a discernible melody and a certain preferred cadence within 10 seconds of hearing a song, or I probably won’t like it. It’s hard to describe though, since I never formally studied music.
For me, it was all for the love of a girl. Untill I developed a crush on a girl my sophmore year, all I listened to was what ever the Top 40 station was churning out. This girl was so cool to me. She liked bands like the Smiths and The Cure and Joy Division. Completely foriegn bands to me at the time. In order to impress this young lady, I studied up on the bands she had scribbled all over her notebooks. Low and behold, I was completely hooked. Thus my education began and my taste developed. I moved from 80s goth/new wave/punk to a lot of indie stuff in the early 90s. I have developed a taste for many little known bands like Mink Lungs and Idaho. I’m still constantly thrilled by new music and I owe it all to her.
Oh, and I got the girl. We dated for most of highschool. I often think about trying to find her again just to thank her.
growing up in 80’s and 90’s, My Parents, TV shows, movies and movie trailers.
Growing up in a small Northwestern town, there were only three kinds of music as a kid–country (still love the older stuff, hate the new stuff), Mexican music (never spoke Spanish and never got into it), and top 40 (which I stopped liking once I became a teenager). I was a loner as a teenager and didn’t like the new stuff (which was in the late 80s), so I listened heavily to oldies, classic rock, and show tunes. Music in the 90s was much better so I started following alt-rock, R&B, and rap. Now it’s mostly a mix of indie and classic rock. So I’d say my taste is self made rather than nurture or nature.
My dad used to listen to Pavarotti singing Neapolitan folk songs, because it made him nostalgic for home. I’ve always liked classical music and opera, I guess that’s where that comes from.
I love really long Baroque sequences with secondary dominants, which I blame on playing NES games like Mega Man.
As a side note, my mom claims that all music is awful noise, and judging by the few albums she owns–Julio Iglesias, The Village People, and U2–I can see why. 
Pot.
Growing up where I did. Bands from Manchester have dominated the UK charts for the last thirty years (Buzzcocks, Durutti Column, Smiths, Joy Division, New Order, Stone Roses, Happy Mondays, James, Oasis, Verve, Elbow, and a million more) and all played a mix of rock/indie that everybody listened to.
First gradually, then suddenly. 
Equal parts of being wired for music/groove in some innate way, exposure to a wide variety of music growing up, and being drawn to the guitar and using the instrument as an anchor-point, from which I could accept and explore more musical genres.
Ultimately, I began to think of Music as an area I wanted to plant a flag in, so I began to proactively research, listen and immerse myself. I learn a lot my taste thinking about which musical branches I have stayed focused on and explored more deeply, and why.
My big brother mostly but a little of my mom too. Because of her I can really get into those oldies but I remember hearing my brother blast (early) Rush, Led Zeppelin and Kiss way back when I was a geekling and thinking it was the best sound I ever heard. That’s the music I grew up on and it’s what I prefer hearing now. I get in to some newer stuff like U2, REM, and Nirvana, and some even newer stuff like The Black Keys and Rodrigo y Gabriela thanks to my daughter introducing me. I’ve never been much for radio listening so unless I go out looking I rarely hear anything else.
My love of music is pretty much innate. I love all types, though my #1 love in theatre musicals. And someone else had to point out to me that musicals cover the whole spectrum of music.
For the most part, the music I love has been influenced by just hearing the right song at the right time. Sometimes I’ve heard a song and either been indifferent or even straight up hated it, and then hear it again months or years later and wonder what I missed. Other times I’m in the right mood when I hear it and fall in love with it right from the start.
That said, I think my taste, despite how obscure it is, actually developed fairly naturally, with a few interesting events in there. I think my natural taste developed hearing random folk, a bit of jazz, and progressive rock and such. From there, hearing Judas Priest at a ripe young age, it was a natural step into progressive metal. From there, it was a natural step into stuff like Metallica as a young teenager, and when I by chance heard Nevermore (Power Metal) and Amorphis (Folk Metal) as a high school senior, I quickly latched onto them and fell into the underground scene. Seeing those bands live, I discovered Opeth (Progressive Death Metal), which allowed me to appreciate the harsh vocals I previously loathed, and all of that opened doors into Melodic Death, Industrial, Black Metal, Death Metal, Avante Garde, and even into a bit of Grind/Deathcore. Of course, that whole time I continued to expand through the other genres I already liked.
simply put: this…
A little nature, a little nurture.
Now? I don’t listen to music. I’ve completely given it up.
I love classical music, Mozart in particular. I can tell you exactly when this started.
An assembly in ninth grade, where we had a local high school orchestra playing Mozart. The girl on first violin had a PHENOMENAL ass.
Its why I started playing viola as a lad. Too bad I lacked any talent.
Anecdote alert. I was playing a track from The Kill’s new album in my car, and my mum’s comment was “I don’t know what this is, but I like it”. She often likes pieces I do, regardless of the genre. This isn’t a nurture thing, as there was little music played in our house when I was growing up, and my preferences developed later. I do tend to think nature plays a strong role in musical preferences.
In my own experience, my first reaction to something new is instinctive. I’ve certainly developed my tastes over the years, I now listen to a much wider range than I used to. Many times, I’ve learned to like something I was initially indifferent to. However, I’m not sure I’ve ever learned to like a piece I initially took a dislike to.