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The award-winning duo Opus Two has been internationally recognized for its “unanimity of style and spirit and close rapport” and for its commitment to expanding the violin-piano duo repertoire. Violinist William Terwilliger and pianist Andrew Cooperstock have performed together for over 30 years across six continents, from Carnegie Hall and Lincoln Center in New York, to Paris, Kiev, Quito, Beijing, and more. The duo has been broadcast live on NPR, Performance Today on American Public Media, Radio France, BBC, Australian Broadcasting Corporation and Radio Television Hong Kong.
Highlights of recent seasons include recitals and concertos on tour in Europe, including Nice, Monaco, Bern and Geneva; a return to Hong Kong for recitals and master classes at Hong Kong Baptist University and Chinaʹs Guangxi Arts University, two 20‐city tours across the United States, and a Sondheim program at 54 Below on Broadway.
Their discography includes the 2025 album Opus Two Celebrates Stephen Sondheim (Bridge Records), hailed as “a winner” by BBC Magazine, and Leonard Bernstein: Violin Sonata; Piano Trio; New Transcriptions (Naxos) featuring world premiere recordings of arrangements by Eric Stern. The duo’s other albums are each devoted to an American composer, including Aaron Copland, George Gershwin, Paul Schoenfield, Lowell Liebermann and Robert Starer.
Terwilliger and Cooperstock are directors of the Global Seminar: Chamber Music France, an annual summer program for American college students which they founded in 2025. They have served as artist-faculty at the Australian Festival of Chamber Music, Brevard, Round Top, and the Saarburg Festival (Germany), among others, and presented master classes worldwide from Juilliard to the China Central Conservatory. They have collaborated with the Takacs, Emerson, Juilliard and Ying Quartets, the Dorian Wind Quintet, cellists Lynn Harrell and Andres Diaz, and many other noted performing artists.
Dr. Cooperstock is Professor of Piano at the University of Colorado, and Dr. Terwilliger is Professor of Violin at the University of South Carolina.
Updated September 2026
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