Conversation so far:
When was David Gilmour Born?
David Jon Gilmour was born on 6 March 1946.
Where was David Gilmour born?
David Jon Gilmour was born in Cambridge, England.
What was the name of David Gilmour's mother?
David Jon Gilmour's mother was mother, Sylvia (née Wilson),
what did David Gilmour's mother do?
David Gilmour's mother, Sylvia (née Wilson), trained as a teacher and later worked as a film editor for the BBC.
What was David Gilmour's father's name?
David Gilmour's father was Douglas Gilmour.

Question: what did his father do?
Self-contained rewrite: what did David Gilmour's father do?