Solo singer-guitarist Bill Bastian came to Duluth in 1987 as a classical singer of opera and art songs. Over the next 35-plus years, his work expanded to almost every form of music popularized by the mid-20th century. “I gradually found myself pretending to be a cover band using opera arias as the basis for my repertoire,” he said. “Though I do make significant forays into music of a blues and pop nature, since I am ultimately a child of the ’60’s.” A longtime voice instructor at the College of St. Scholastica, Bastian performed a Christmas concert in December with the Highland Quartet.