Conversation so far:
When was the pinnacle of Willies career?
Dixon signed with Chess Records as a recording artist, but he began performing less, being more involved with administrative tasks for the label.
By 1951, he was.
What happened in 1951?
By 1951, he was a full-time employee at Chess, where he acted as producer, talent scout, session musician and staff songwriter.

Question: Was he successful in his new positions?
Self-contained rewrite: Was Willie Dixon successful in his new positions?