In 1946, Hillyer founded the Juilliard String Quartet at the Juilliard School in New York along with Robert Mann and Robert Koff, who both played the violin, and cellist Arthur Winograd. Although Hillyer was unsure of the Quartet's potential for success, his father, Dartmouth mathematics professor Louis Silverman, strongly encouraged him to remain committed, Reiko Hillyer said.
Anthony Princiotti, a violin professor and Dartmouth Symphony Orchestra conductor, said that Hillyer's contributions to Julliard led to the school's rise to prominence.
"From the standpoint of an American musician devoting one's life to what is essentially a European art form, the significance of what was going on in the 1950s in New York City was seminal," he said in an interview with The Dartmouth.
Hillyer's Quartet quickly established itself as a selective and prestigious group and focused on adding a new sense of energy to a classical repertoire, according to Princiotti.
"They developed approaches to the art that seemed to be quintessentially American in terms of energy, eclecticism and a general attitude of newness and exploration," Princiotti said. "They gave us an idea of how we might identify with the art while still retaining a sense of native authenticity."
For inspiration, Hillyer often listened to a range of composers' music. He viewed Bach's works as a form of "musical prayer" and also enjoyed listening to Mozart and Beethoven, Reiko Hillyer said.
"I could never ask him what his favorite composer was," she said. "He loved so many."
As Hillyer enjoyed the music of Hungarian composer Bela Bartok, the Quartet became famous for its unique interpretation of Bartok's works, as well as those of other contemporary composers such as Elliot Carter, Milton Babbit and Ralph Shapey.
"He really introduced contemporary music onto the American map," Reiko Hillyer said. "A lot of people during this time considered Bartok's music to be as radical as rock music."
Hillyer also excelled as a professor, according to his daughter. He held professorships at American University, the Curtis Institute, Juilliard, the Yale School of Music and Harvard University. In 1981, he became a viola and chamber music professor at Boston University's School of Music, where he delivered his last lecture three weeks before he died.
"As a teacher who taught for 50 or 60 years, he influenced many, many generations," Reiko Hillyer said.
Hillyer's students appreciated his focus on musical phrasing and the way in which he taught them to look at musical impressions as a whole rather than specific notes, according to Reiko Hillyer. Hillyer also encouraged his students to develop interpretation skills and concentrate on self-expression.
Reiko Hillyer said that Hillyer's students described him as "very stern" but also full of "humor and warmth." Many of his students characterized his teaching style as "the perfect blend," she said.
Boston University music professor Steven Ansell described Hillyer as a well-rounded individual with curiosities that extended beyond music.
"With his incisive intelligence, [Hillyer] was constantly learning, studying languages and mathematics," Ansell said. "Hillyer was an inspiration in many ways through his performances, recordings and collaborations."
Born into a musical family, Hillyer developed a passion for the arts as a young child and began studying the violin at seven years old. As an undergraduate at the College, Hillyer played for the Orchestra, which his father founded.
After graduating, Hillyer continued his study of music at Harvard University. While in Cambridge, Hillyer established an intimate lifelong friendship with his classmate and famous American composer Leonard Bernstein, who later composed and dedicated a violin sonata to him.
Although Hillyer traveled around the world to compose and perform music, he remained committed to the College and returned several times to host concerts for the Dartmouth community, according to Reiko Hillyer.
