Human: In the movie ‘The Barbary Coast’, why did the pirates have a harp? Assistant: 
The pirates in the movie The Barbary Coast had a harp because it was a prop. A harp is a stringed musical instrument with a soundbox and a neck. The strings are plucked with the fingers or a plectrum. The soundbox amplifies the sound of the strings. The harp was a popular instrument in the early 19th century.