Postcard from New Orleans, showing a "second line" jazz band. The "main line" or "first line" is the main section of the parade; those who follow the band just to enjoy the music are called the "second line". It's a New Orleans tradition that is thought to have its origins in West African circle dances, where children formed a periphery circle outside the main circle of adult dancers. The dance was brought by slaves to New Orleans, where it became incorporated into processions, such as funerals, forcing the ring to straighten into a line.
Many thanks to friend Paul who was in New Orleans for a conference.
Fairly commonplace American flag "Forever" stamps, sans postmark, but plus a Mardi Gras logo.