Second line is a tradition in brass band parades in New Orleans, Louisiana. The "main line" or "first line" is the main section of the parade, or the members of the actual club with the parading permit as well as the brass band. Those who follow the band just to enjoy the music are called the "second line." The second line's style of traditional dance, in which participants walk and sometimes twirl a parasol or handkerchief in the air, is called "second lining." It has been called "the quintessential New Orleans art form – a jazz funeral without a body." Another significant difference from so called "jazz funerals" is second line parades usually lack the slow hymns and dirges played at funerals (although this is not a hard rule; some organizations may have the band play something solemn towards the start of the parade in memory of members deceased since their last parade).
Some scholars believe that second lining has its origins in traditional 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. Others note the similarity of the steps – exaggerated, loosely coordinated strutting – to dances performed in Congo Square by the enslaved given the day off on Sundays. These dances were officially banned for a time because they were deemed threatening to the white inhabitants of the city, and their resurgence in second lining suggests a similar celebration of individual freedom.
After the Civil War, African and African-American traditions came to be merged with the military brass band parade traditions of the Europeans and white Americans. Insurance companies often refused to cover the recently freed formerly enslaved, so African Americans formed into Benevolent Societies and "Social Aid & Pleasure Clubs". Membership benefits usually included a brass band for funerals and at least one public parade with music a year, so such societies became important in establishing the second line traditions.
The Second Line – the magazine of the New Orleans jazz club, started in 1950 – took its name from the second lining tradition, which by that time included fans of jazz music, both black and white.