secondline

Secondline is a term used in several domains to denote a secondary or supportive layer, or a cultural practice associated with street parades. The most widely recognized use is in New Orleans, where the “second line” describes the group of dancers and onlookers who follow a marching band in a procession.

In traditional second line processions, the first line is the parade's main brass band; the second line consists of people who accompany and improvise moves, waving handkerchiefs or parasols, creating a communal, celebratory atmosphere. The term has historical roots in 19th-century funerals and social parades and has evolved into a broader urban music and dance culture outside funeral settings.

In governance and risk management, the second line of defense is the function that oversees risk controls, compliance, and policy implementation, supporting the first line of front-line operations. In widely adopted models with three lines of defense, the second line provides oversight and assurance, while the third line is internal audit.

In information technology and customer support, second-line or second-line support refers to specialists who handle escalated issues that first-line staff cannot resolve, offering deeper technical expertise and more time-intensive troubleshooting.

In military or logistics contexts, the term can denote a secondary defensive line behind the main front, or a reserve of personnel and supplies used to reinforce the front or secure critical rear areas.

Related topics include the three lines of defense risk model and the New Orleans second line tradition.