Choro has been described as "the New Orleans jazz of Brazil." It is a complex popular musical form based on improvisation, and like New Orleans jazz, blues, or ragtime, grew from a formalized musical structure and many worldly influences.
Choro was developed as an almost purely instrumental rather than vocal style because of the musicians' sheer love for playing. All-night jam sessions became very common from the 1920s to the 1940s, and at these gatherings the players formed an almost spiritual connection with their music. To be accepted at the jams one needed to be a good enough instrumentalist as well as understand the musical "code words"—the language of improvisation.
In the hands of virtuosic performers, choro music is sublime. Mike Marshall and Choro Famoso are just such a group of performers. These are the American ambassadors of choro.
Here is video of the group performing "Receita de Samba," by Jacob do Bandolim