Lost Chopin waltz discovered almost 200 years after it was written

A new piece of music believed to be by the Polish composer Frederic Chopin has been discovered. The unknown waltz was unearthed in the vault of the Morgan Library and Museum in New York. The rare manuscript - dated between 1830 and 1835 - was discovered by curator Robinson McClellan while he was cataloguing new collections. He then worked with a leading Chopin expert to authenticate the score.