He shrugged a bit at Qrow's words. "It works for me," he said, after a moment. "It also keeps my mind occupied, which is something I desperately need." Sherlock was not someone who handled being bored well. Not at all, actually. And playing the violin was something that he could do to help.
Sherlock studied Qrow for a moment, observing him. Observing the fact that he had a flask on him. He was positive that said flask had alcohol in it. What else would it have? Most people didn't drink anything non-alcoholic from flasks.
"Ever since I was a child," he said, in response to Qrow's question. "I taught myself out of boredom."