It's funny, in high school, we attended assemblies in the Quincy Jones Auditorium. Jimi Hendrix and Bruce Lee attended the same high school, which we all knew, but Quincy Jones just didn't have the same name recognition. Despite his name being right in our faces so frequently.
Over the decades since I graduated, I've taken some time to learn about the incredible influence he's had on the arts. Just recently, I learned that an actor I've watched in a few shows, Rashida Jones, is his daughter.
To briefly answer your question, his occupation was producer, arranger, composer and songwriter. Such folks often don't get name recognition without extensive self-promotion. You might be familiar with his work, without learning his name because he wasn't on the headline. But his work went deeper than that -- he was a community builder; that's work which is hard to measure the value of: to anybody that doesn't post here... who is Paul Graham?
I stand by the part where I said we all "knew" it at the time; his picture was included in a mural and everything! But, thanks, TIL! Your reference doesn't support the negative claim, but I found a really cool deep dive here: https://iexaminer.org/uncovering-bruce-lees-public-school-ye...
and "We are the world", and The brothers johnson and some stuff with Miles Davis and Sarah Vaughn and many many others. It's absolutely absurd that one person did that range of things.