Audiences of the Danish String Quartet know that the ensemble likes to blur the boundaries between folk music and classical music. In this concert, the four Scandinavians combine traditional melodies by 18th­-century Irish harper Turlough O’Carolan with works from different eras to create a sound world that transcends styles and genres. In addition to Stravinsky’s Three Pieces for String Quartet, which evoke Russian dance rhythms and sacred chants, the program includes Mozart’s delightful F-­major Divertimento and Caroline Shaw’s Haydn­inspired Entr’acte.