Witold Lutosławski gave the title Subito to the violin showpiece that he wrote for a competition in 1994, a work designed to evoke delighted astonishment and a piercing moment of musical communion between performer and listener. For her debut album—very much in this vein—Julia Hwang casts her effervescent bow over this, and contrasting works by Grieg, Vaughan Williams and Wieniawski.