Much Ado, the solo debut album by Korean-American violinist Danbi Um is as striking for the young musician’s choice of “old world” repertoire as her virtuoso interpretations and the sumptuous sound she draws from her 1683 “ex-Petschek” Nicolo Amati violin. Danbi conjures memories of a musical Golden Age, a sensibility instilled in her by a roster of internationally renowned tutors.