Steiner was NEC's first non-musician president. After graduating from Harvard Law School, he practiced law and worked in government. In 1969, he became secretary of Harvard's University Committee on Governance; he spent the next 27 years at the university, as general counsel, vice president, and lecturer in public policy. He became a member of the board of NEC in 1995 and was named acting president in 1999.

During his tenure, NEC created a joint-degree program with Harvard and a chamber music training program, boosted financial aid, and hired such faculty members as violinist Donald Weilerstein, violist Kim Kashkashian, pianist Bruce Brubaker, jazz saxophonist Steve Lacy, and flutist Paula Robison. Steiner raised $72 million over the last three years as part of a $100 million capital campaign.

His goal, according to a statement from NEC, was to make "NEC a school at the top of its field like Harvard or MIT."

"Daniel Steiner meant so much to NEC during his tenure of seven years," said board chair Jack Vernon. "He introduced changes which will set the direction for the conservatory for years to come with his recruitment of distinguished faculty."

Harold Pratt, vice chair of the board, said, "With his passion for the school, his concern for people, his insistence on excellence, his modesty, gentleness, integrity, and sense of humor, he created an environment of mutual respect and collegiality. He liked to say 'NEC is a happy place' and he was right."