And now.....everybody raise the leg!!!!!

These street musicians were playing the Cuban song "Son de la Loma" The title is a pun with the word "Son": They are, or "Son": a Cuban rhythm.
Anyway, throughout Latin America it's better known as "Mamá, ¿de dónde son los cantantes?", something like Mom, where does the singers come from?
Sorry, but the title sounds better in Spanish.