A minstrel is a freelance musician and entertainer, skilled with a lute or similar instrument, specifically one that allows them to play a tune while also singing.
Minstrels are usually found in taverns, inns and on the street, earning money from happy patrons at the grace of the owner of the establishment. The payoff for the owner is a good minstrel will attract customers, and happy customers spend more coin.
While players are generally free to select a citizen role as a background, they should check with the Dungeon Master to make sure it fits within the local area, other party members and does not conflict with the intended adventure.
Citizens have proficiencies in weapons and armour relative to their type and region, so it is not included in the above information, and players do not gain any proficiencies from choosing a citizen background.