The Queen of the drums (Rainha de Bateria)

Baterias  are preceded by a queen (or rainha da bateria), that can be either a beauty from the community or some TV star or VIP, plus a number of princesses (girls fight fiercely for the position).

They naturally draw everybody's attention as they look and introduce the band to the audience.
The queen of bateria goes infront of the bad. 
It's good manners to stand up and cheer. The positron of the Queen is a great honour in the tradition of  Carnival.