If you know anyone that "seriously" collects records, they are probably exactly like this guy.
They organize their collection by sections for generic metal, stoner metal,death metal, punk, shoegazer, dream pop, jazz, ragtime, classical, rap, R&B etc. etc. etc. If the records aren't organized by genre, they might just be ordered chronologically, alphabetically, or maybe even autobiographically (by a timeline of how the owner bought them).
The record collector will show you the records that changed their life (all of them), and the records you need to own (all of them).
"I'm not a DJ, but..."