NEFFA is a participatory festival; attendees are encouraged to participate in dancing, singing, musical jam sessions, and other activities.

Numerous New England folk dance callers, leaders and musicians have had formative experiences at the festival, and in turn have inspired and influenced thousands more through their performances, workshops, and enthusiastic participation.

It is the inspiration for other similar traditional dance and music festivals throughout the United States and North America.

Mary Gillette envisioned a festival where New England's many ethnic groups could share their song, dances, and crafts and present them to a wider audience, in a simple, honest, straightforward manner.

Philip Sharples, who in 1940 had founded the Belmont Country Dance Group (one of the first square and contra dance series in the Boston area), joined with Mary Gillette and Ralph Page in calling local leaders to meet and talk it over.

From the start, the Festival Committee agreed to maintain an atmosphere of non-commercialism and high standards of performance and authenticity.

A variety of concerts, discussions and other more intimate performances take place in numerous class room spaces.

The hundreds of volunteer musicians, singers, dance callers, leaders and dance-demonstration performers are primarily from New England and every year a number arrive from more distant parts of North America.

In addition to the annual spring festival, NEFFA conducts the weekly Thursday Night Contra dance, formerly in Cambridge and as of 2006, held at the Concord Scout House.