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 On Nov. 23, the Harmonizers will perform a mixture of ’60s favorites, American classics and a hint of the winter season when they sing at the Northbrook Public Library, 1201 Cedar Lane in Northbrook. The concert will begin at 2 p.m.

Celebrating more than 60 years of four-part, a cappella singing, the Harmonizers perform at their own public concerts, at special and holiday programs for senior citizens and other Chicago-area groups throughout the year, and at farmers markets during the summer and fall.

More information is available at or 847-454-7535.