Conversation so far:
When did Rudy Van Gelder begin recording?
From 1946, Rudy Van Gelder recorded in his parents' house in Hackensack, New Jersey.
Who did Rudy Van Gelder work with during his early career?
In the 1950s, Rudy Van Gelder performed engineering and mastering for the classical label Vox Records.

Question: How did he become interested in music?
Self-contained rewrite: How did Rudy Van Gelder become interested in music?