WESTPORT — The “Nassoons,” a Princeton University a cappella group that is among the nation’s oldest, will perform Oct. 18 at the Unitarian Universalist Congregation in Westport.

The performance is set for 7 p.m. Wednesday, Oct. 18, at the congregation, 10 Lyons Plains Road.

There is no charge to attend the concert, but organizers encourage donations to the Domestic Violence Crisis Center based in Norwalk.

The Nassoons, the fifth oldest collegiate a cappella group in the nation, founded in 1941, will perform vocal interpretations of popular music ranging from the 1940s to contemporary selections, according to event organizers.

“Beachside Express,” a male a cappella ensemble from Greens Farms Academy, will perform in advance of the Nassoons.

For questions, contact the Rev. Ed Thompson, the congregation’s minister of music, at 203-227-7205, ext. 18, or ed@uuwestport.org.