Mazzoli was born in Lansdale, Pennsylvania, on October 27, 1980. She attended the Yale School of Music, the Royal Conservatory of the Hague (studying there with Louis Andriessen, a major influence), and Boston University. Among her other teachers were Aaron Jay Kernis, John Harbison, Richard Ayres, and David Lang. She taught composition for a year at Yale and then moved to New York to take a position as executive director of the MATA Festival, oriented toward the promotion of young composers, between 2007 and 2010. During this period she founded the quintet Victoire for the performances of her own compositions; with its mix of electronic and acoustic instruments, it lay somewhere between a band and a classical chamber ensemble. She has released three albums with Victoire, beginning with Cathedral City in 2010; the 2012 album Song from the Uproar was drawn from Mazzoli's first opera, and 2015's Vespers for a New Dark Age featured percussionist Glenn Kotche (of the alternative country band Wilco). It was for vocal works, including Song from the Uproar (based on the story of Swiss explorer Isabelle Eberhardt), that Mazzoli first gained wide attention. For that and for subsequent operas, she has collaborated with librettist Royce Vavrek, dubbed "the indie Hoffmansthal." Song from the Uproar was performed by several American companies and had its premiere in Vienna in 2018. Mazzoli's 2016 opera Breaking the Waves was based on the 2006 film of the same name by controversial Danish director Lars von Trier; that work, co-commissioned by Philadelphia Opera, won the Music Critics of North America Association Award for Best New Opera. Mazzoli has also been a prolific composer of instrumental music, with works performed by, among others, the BBC Symphony, the Kronos Quartet, the JACK Quartet, eighth blackbird, the Detroit Symphony, the American Composers Orchestra, the Australian Chamber Orchestra, and the Los Angeles Philharmonic. Performers are attracted to her music range, notably, from established traditional ensembles to contemporary groups of various kinds. In 2018 Mazzoli, selected by conductor Riccardo Muti, earned a two-season, composer-in-residence slot with the Chicago Symphony Orchestra, and her opera Proving Up was premiered that year. She is on the faculty at Mannes College of Music. ~ James Manheim, Rovi