Plena is an Afro-Latino tradition that developed out of bomba music around the beginning of the 20th century in southern Puerto Rico. Plena lyrics are narrative. They convey stories about events, address topical themes, often comment on political protest movements, and offer satirical commentaries. Plena instrumentation has changed greatly over the years, but the one indispensable and defining element is the pandereta, a round hand drum that comes in different sizes. The smallest of them is the requinto, which improvises over the rhythm of the other drums. The members of Los Pleneros de la 21 demonstrate the pandereta and explain its role in plena music.