Arthur Tillman Merritt, who for 40 years worked in Harvard's music department as professor and chair, died on Sunday in Bedford, Mass. He was 96.

Merritt's colleagues remembered him as passionate about music and teaching.

"Never having married, his sole thrust was music, and then it developed into Harvard music, and then specifically, the development of the department," said Elliot Forbes '40-'41 professor emeritus of music and a close friend of Merritt.

"He was on fire about music," Forbes said.

Born in Calhoun, Mo., in 1902, Merritt first attended the University of Missouri and later came to Harvard, earning a master's degree in music.

In 1932, Merritt joined the Harvard staff as a music instructor, and he became a full professor in 1943.

From 1942 to 1952 and again from 1968 to 1972, Merritt served as the chair of the music department. There he was responsible for raising most of the money for the Mason Building and for several named professorships.

The addition of the Mason Building, part of the larger music complex that includes Paine Hall, motivated Merritt to again become chair of the department in 1968.

"He got so excited about the addition to the building that he was willing to do it," said Forbes. "He was so ambitious for the department, not self-ambitious."

Merritt is known for a symposium on music criticism he organized in 1947. An international audience gathered to hear speakers and music premiers that Merritt commissioned.

He taught full time between his terms as chair. Though his specialty was Renaissance music, topics for Merritt's class included harmony, counterpoint and the history of music.

Students remembered him as a professor who made time for undergraduates.

"He was as at home teaching undergrads as he was grads," said Forbes, who studied under Merritt in the late 1930s and early '40s.

Merritt was a tough, effective teacher, former students said.

"For me, he was the very best teacher," said Richard F. French '37, a former student and colleague of Merritt. "He was demanding and strict and got results."

Through spending 40 years at Harvard as a teacher and living in Eliot House, Merritt developed relationships with the students, too.

"He was close to students all right, particularly the ones he had in courses and tutorials," Forbes said.

After retiring in 1972, Merritt continued to research music and publish editions of Janequin and Andrea Gabrieli's works. He also established a music program at Trinity College in Hartford, Conn.

"More than anyone, he was my mentor," Forbes said.