He is Music Director of Mill City Summer Opera in Minneapolis and Artistic Director of the Alpha Omega Ensemble in New York City. He’s performed with the Israel Chamber Orchestra, Music Saint Croix, New York City Opera, Florida Grand Opera, Glimmerglass Opera, Opera Theater of Saint Louis, American Opera Projects, American Lyric Theater, and Ash Lawn Opera Festival.

DeMaris has taught at Lawrence University, New England Conservatory School of Continuing Education, George Mason University's International Opera Alliance, and the International Vocal Arts Institute in Tel Aviv.  He is the Director of Opera and Musical Theater at Ithaca College and on the faculty of the Aspen Music Festival. He has served on panels with Opera America and presented master classes with the New York State Music Teachers Association. His students have performed on Broadway, in national and international tours, and at opera companies and festivals throughout the United States.

DeMaris has performed at the United Nations, the Aspen Music Festival, Boston’s Jordan Hall, New York’s Studio 54, Jazz at Lincoln Center, Symphony Space, Alice Tully Hall, Skirball Center, and La Maison francaise, and in recitals, competitions, and master classes throughout the United States and abroad.

A frequent performer and advocate of contemporary music, he has worked closely with composers Stefan Weisman, Lee Hoiby, John Harbison, Mark Adamo, John Corigliano, Peter Ash, and Richard Rodney Bennett. He conducted the Middle Eastern premiere of Mark Adamo's Little Women with the Israel Chamber Orchestra and the world premiere of Weisman's Darkling with American Opera Projects at the Classical Stage Company with additional performances in Gniezno, Poland, at Frei Universität in Berlin, Germany, the New York City Opera VOX Festival and the United Nations. He also leads the world premiere recording of Darkling, released on Albany Records in 2011. DeMaris was also involved with the professional American premiere of Richard Rodney Bennett’ s Mines of Sulphur at Glimmerglass Opera, which was broadcast on NPR and BBC, released on the Chandos label, and nominated for a Grammy Award, as well as the world premieres of Peter Ash's The Golden Ticket and John Corigliano's revised version of The Ghosts of Versailles at Opera Theater of Saint Louis. He also serves as Resident Conductor of American Lyric Theater in New York, through which he has done several workshops of new works including The Golden Ticket at Jazz at Lincoln Center and Adam and Eve at Symphony Space. Mr. DeMaris is also a composer himself: his art songs have been performed at Glimmerglass Opera, Central City Opera, Ash Lawn Opera Festival, and in recitals throughout the United States.

Originally from Lancaster County, Pennsylvania, he and is wife Amanda live in Ithaca, New York.