The title does indeed not make much sense, but I imagine OP is trying to ask: "What grown up music did you listen to that you, and not a grown up, put on."
Answering that question, the first artists I remember looking up and having on my phone/mp3 Player were 30 seconds to Mars, Foo Fighters, and Linking Park. The latter because it was all the rage when I first got into music, not because the songs were especially good.
In the mid 1970s, we could borrow cassettes from the library. I started with Neil Diamond “His 12 Greatest Hits”, then moved on to Electric Light Orchestra, Roxy Music, and Mike Oldfield.
I assume you're asking what was the first non kids music I listened to and picked out myself? Instead of listening to the Lion King sound track, my first CD was Boston's greatest hits.
Found my parents "Business as usual" - Men at work vinyl.
Memorized "Down Under" listening with Sony DR-S5s. I always thought that's how you were supposed to listen since the cord matched the one on the album cover.
Eminem curtain call. My grandma brought it for me having no idea what it was. I was listening to it for a few days before my mum was like wtf is that and then listened to the first song on the album which was fack. I was 9 or 10 and she confiscated it and I had to steal it back and rip it to the computer and create copies incase she got those.
I remember making back up's of songs I liked that had swearing in them when i was like 8 in case my mom found them. I think I had like 5 or 6 copies of Damnit by Blink 182 hidden in my folder on the family computer, which had an 8gb hard drive.
The first CD I ever owned was O zone - Dragon Sta Din Tei aka the Numa Numa song. No idea why or where I got it from but I would listen to that on my little cd player
My parents were young so I never had kid music. I listened to their stuff. The earliest I can recall I had 45s and albums in my room: Three Dog Night, Eagles- Hotel California, Paul Simon - 50 ways to leave your lover on 45, the soundtrack to Saturday Night Fever. I had several Beach Boys albums, and The Bay City Rollers album whichever one had Saturday Night on it. Oh, and KISS Double Platinum.
My first album was the self titled Gorillaz. If you put it in a computer there was a game!
I'd been listening to my older brother's music for a while before that though - Green Day Dookie, Blink-182 Enema of the State, Weezer Blue Album, Korn Issues were all in the mix.
I loved playing with my bigger sister's cheap hi-fi, I would put on a vinyl record and without power turned the record manually save heard whispering ^(🎵cherry cherry lady...🎶), so there's Modern Talking, then when she bought a CD player it was Crush by Jennifer Page