Soprano Julia Bullock prefers to be called a "classical singer." It's a rather humble, even vague, appellation for one of today's smartest, most arresting vocalists in any genre. She was just named Artist of the Year by Musical America, who labeled her an "agent of change." Bullock, who also considers herself an activist, has shaken up the classical music world recently with provocative programming and expressive performances. You can witness just that in this extraordinary Tiny Desk (home) concert from Munich, Germany with pianist and conductor Christian Reif, whose sensitive playing seems to anticipate and enhance Bullock's every phrase. He also happens to be her husband.