Conversation so far:
What started Billy Joel's solo career?
Billy Joel signed a contract with the record company Family Productions with which he recorded his first solo album, Cold Spring Harbor.
Where was Cold Spring Harbor?
Cold Spring Harbor is a town on Long Island
What was Billy Joel's debut album called?
Billy Joel's debut album was called Cold Spring Harbor.

Question: Who helped him with this
Self-contained rewrite: Who helped Billy Joel begin his solo career?