Honestly, I’m a classically trained musician, so I almost never put on classical music for background noise - I tune in and listen out of sheer habit.
I like Philip Glass. Yeah his name is a punchline but I find his sense of harmony and melody pleasant to listen to. I recommend his violin concerto. If you like vocal music I recommend renaissance motets (anything by Tomás Luis de Victoria for starters).
If you like a challenge take a listen to Stravinsky. If you wanna hear what it’s like to be a combat veteran try Xenakis.

I knew a guy who was, by all objective standards, a musical genius. Brilliant songwriter and lyricist, prolific, could master an instrument in weeks, took to sound production and engineering like a fish to water. In a sane world, he’d have easily flourished in the music business and possibly even made it big, as he had the drive. He had a razor sharp wit and a relentless sense of humor, and in his lucid moments, was a blast to be around.
Except he was an irredeemable and unapologetic pedophile. He had previously done ten years for making and distributing cp by the time I had met him. When I brought it up he vehemently defended himself and his vice as being completely normal and natural, and even bragged about his “work.” He insisted that he did nothing wrong and seemed to genuinely not understand why people didn’t accept it.
Shortly after we parted ways, I learned that he got caught again hoarding thousands of pictures and videos. He’s currently in prison and will spend the rest of his life there.