This summer we've been telling you about a project called Songs in the Key of L.A., the multi-platform collaboration between the Library Foundation of Los Angeles, the L.A. Public Library and USC professor Josh Kun. 

Kun and his students culled through thousands of pieces of sheet music to find songs about the Golden State. 

Today, Kun introduces us to the 1930s song "Chiapanecas," which became known during that time as the Mexican hand-clapping song.