The setup is a familiar one: talented young string quartet is heard by wealthy donor who, taken with their skill and enthusiasm, sets the foursome up with priceless old Italian instruments which they could never otherwise afford. But in the case of the Miró Quartet, one of a small number of headline-grabbing young quartets vying to be the next Juilliard or Guarneri, their benefactor was a North Carolina musician who wanted to see if a collection of specially crafted modern instruments could elevate the group in the same way that four Strads could. The result was a specially commissioned set of two violins, viola, and cello, tailored to meet the Miró’s needs. And the results? Well, it depends on which player you ask.