Original: The season's music was composed by "The Track Team", which consists of Jeremy Zuckerman and Benjamin Wynn, who were known to the show's creators because Zuckerman was Konietzko's roommate.
Simplified: The season's music was written by "The Track Team", which consists of Jeremy Zuckerman and Benjamin Wynn, who were known to the show's creators because Zuckerman was Konietzko's roommate.