Complex sentence: He sang in the choir at St. David's Episcopal Church and became a member of the "Hill City Quartette", a group of young men who sang at gatherings and serenaded young women of the town.
Split into simpler sentences: He sang in the choir at St. David's Episcopal Church. He became a member of the "Hill City Quartette", a group of young men who sang at gatherings and serenaded young women of the town.