Conversation so far:
Where was he born?
Sandberg was born in Stockholm.
Where did he grow up?
grew up in the suburb Stenhamra, Ekero Municipality.
When did he become a singer?
As a child.
What did he do as a child to help his singing career?
Martin was a student of Sweden's public music-education program.

Question: Was he in a band?
Self-contained rewrite: Was Max Martin in a band?