Ira Klein is a Cambridge guitarist, banjoist and composer. (Photo: Ira Klein via Facebook)

A free outdoor concert is offered Saturday on a recently refurbished Palmer Street in Harvard Square by Club Passim, the Harvard Square Business Association and the Folk New England organization.

Boston-based, Indiana-raised (and Longy School of Music grad) Sadie Gustafson-Zook and Cambridge guitarist, banjoist and composer Ira Klein will perform outside Club Passim, 47 Palmer St., where there will be roasting chestnuts from Busa Farms prepared by El Jefe Taqueria and HSBA staff. Chairs will be set out, but people are reminded to bring blankets for a day not expected to get any warmer than 53 degrees.

The event is part of the the 15th Annual Folk Music Month in Harvard Square, said a Monday email from the business association.

“The square has long been an epicenter of critical thinking and social and political reform, and nowhere was it more [potent] than in the folk music scene that had its inception in the late 1950s at Club 47,” said the email from HSBA executive director Denise Jillson.

The free concert runs from 2 to 4 p.m. Saturday. Club Passim plans a paid concert inside from 5 to 8 p.m. Saturday: an intimate performance by Susan Werner, a singer-songwriter celebrating the release of her 16th recording, the New Orleans-themed “NOLA.” King Margo opens. Tickets are $35 available here.