Task: Question Answering
Input (English): The film opens with violinist Roberta Guaspari having been deserted by her US Navy husband and feeling devastated, almost suicidal. Encouraged by her mother, she attempts to rebuild her life and a friend from student days recommends her to the head teacher of a school in the tough New York City area of East Harlem. Despite a degree in music education, she has little experience in actual music teaching, but she's taken on as a substitute violin teacher. With a combination of toughness and determination, she inspires a group of kids, and their initially skeptical parents. The program slowly develops and attracts publicity. Ten years later, the string program is still running successfully at three schools, but suddenly the school budget is cut and Roberta is out of a job. Determined to fight the cuts, she enlists the support of former pupils, parents and teachers and plans a grand fund-raising concert, 'Fiddlefest', to raise money so that the program can continue. But with a few weeks to go and all participants furiously rehearsing, they lose the venue. Fortunately, the husband of a publicist friend is a violinist in the Guarneri Quartet, and he enlists the support of other well-known musicians, including Isaac Stern and Itzhak Perlman. They arrange for the concert to be mounted at Carnegie Hall. Other famous musicians, including Mark O'Connor, Michael Tree, Charles Veal Jr., Arnold Steinhardt, Karen Briggs, Sandra Park, Diane Monroe, and Joshua Bell, join in the performance, which is a resounding success. The film's end credits declare that the Opus 118 program is still running successfully. They also report that the school's funding was restored during the making of the film. 
Question: What instrument does Roberta Guaspari play?
Output (English): The violin.