Belfast Bay Fiddlers will give a free concert on the Rockland Public Library lawn Thursday, July 18, at 6:30 p.m. People of all ages are invited to come early for a picnic and stay for the music. Belfast Bay Fiddlers are amateur musicians who play traditional dance tunes from New England, French and Atlantic Canada, Ireland, Scotland and other regions. Their repertoire includes jigs, reels, hornpipes, polkas and waltzes performed on fiddle, guitar, mandolin, whistle, banjo, bass, piano and other instruments.