Russell Sherman, a pianist admired for his poetic and idiosyncratic interpretations of Schoenberg, Beethoven, Debussy, Liszt and others, died on Sept. 30 at his home in Lexington, Mass. A longtime music educator as well, he was 93.

His death was confirmed by his wife, the pianist Wha Kyung Byun.

Mr. Sherman, who gave his last recital at 88, made his name performing virtuoso works such as Franz Liszt’s daunting “Transcendental Études.” Referring to the composer’s reputation as a showman, Mr. Sherman told The New York Times in 1989 that he was engaged in a “lifelong battle to reconstitute Liszt as a serious composer.”

He recorded the Études on cassette in 1974 and in 1990 for Albany Records. “The poetic idea is central,” he wrote in the liner notes for the second recording, “and the virtuoso elements become so many layers to orchestrate the poetic content.”

Mr. Sherman was in many ways an anti-virtuoso; he devoted much of his time to other interests, like poetry, philosophy and photography. In the late 1950s, instead of becoming a touring concert pianist, he left New York to teach piano at Pomona College in California and the University of Arizona in Tucson.

In 1967, he began a long tenure at the New England Conservatory of Music in Boston, hired by its president at the time, the composer Gunther Schuller. Mr. Schuller, who founded GM Recordings in 1981, produced a Beethoven album by Mr. Sherman, who became the first American pianist to record the complete Beethoven sonatas and piano concertos.

On a GM Recording album, “Russell Sherman: Premieres and Commissions,” Mr. Sherman performed works composed for him in the 1990s by Mr. Schuller, Robert Helps, George Perle and Ralph Shapey. His recordings also include works by Claude Debussy and Arnold Schoenberg, as well as Chopin Mazurkas, the complete Mozart Piano Sonatas and Bach’s English Suites.

Mr. Sherman began giving public concerts again in the 1970s. He performed with the New York Philharmonic, the Los Angeles Philharmonic, the Chicago Symphony Orchestra, the Philadelphia Orchestra and the Boston Symphony Orchestra as well as major European orchestras.

His concerts drew devoted fans who admired his dramatic interpretations. In 2016, the critic Jeremy Eichler of The Boston Globe wrote that in works by Schoenberg, Beethoven, Debussy and Liszt, Mr. Sherman’s playing, “while still demonstrating a formidable athletic prowess, also conveyed his abiding gifts of fantasy and insight.”

His idiosyncrasies were often noted. Reviewing a performance of Liszt’s Sonata in B minor and two Beethoven sonatas at Carnegie Hall in 1984, the Times critic Will Crutchfield wrote: “It is possible to feel that he distorts, infuses too much into little,” but added that it was “better instead to salute in Mr. Sherman’s concert an antidote to the many that are played week after week in which listeners are lucky if their interest is genuinely caught once or twice in the whole evening.”

Some two decades later, Allan Kozinn wrote in The Times that Mr. Sherman’s “interpretive style, it should be said, is an acquired taste,” but that his “performances are usually illuminating alternatives to the standard view.”

Mr. Sherman resented these accusations of eccentricity. “I think of myself as a compassionate conservative” who responded “radically to the score and nothing but the score,” he told The Times in 2000. He suggested that listeners who disliked his interpretations lacked imagination.

Russell Sherman was born on March 25, 1930, in Manhattan and lived at the elegant Essex House hotel on Central Park South with his parents and three older brothers. Their neighbors included Rudolf Bing, the general manager of the Metropolitan Opera; the opera singers Lauritz Melchior and Lily Pons; and the pianist Clifford Curzon.

Mr. Sherman’s father, Moses Sherman, was a manufacturer of women’s raincoats, and his mother, Irene (Schwartz) Sherman, was a homemaker. Russell inherited his father’s love of fashion.

He started piano lessons at age 6. At 11, he joined the studio of the Polish-born pianist and composer Eduard Steuermann, who had studied with Schoenberg and Ferruccio Busoni and who encouraged his students to take interpretive risks. This inspired Mr. Sherman’s own ethos that performers should strive for what he called “personal wildness and conviction” in their interpretations.

He made his concert debut at 15, at Town Hall in Manhattan, and began undergraduate studies at Columbia University the same year. He graduated with a degree in the humanities in 1940 and later studied composition with the German composer Erich Itor Kahn.

Mr. Sherman married Wha Kyung Byun, a Korean-born former student of his, in 1974; she began teaching at the New England conservatory in 1979. They sometimes celebrated their anniversaries by performing together.

In a phone interview, she recalled soirees at their house, where students would read different roles in Shakespeare plays. Mr. Sherman, a passionate baseball fan, was also an avid photographer with an interest in light, shadows and trees. He often read science books, determined to master concepts he initially found challenging.

While teaching at the New England Conservatory, he was also a visiting professor at Harvard University and at Juilliard in New York. He and his wife sometimes taught the same students, such as the pianist Minsoo Sohn, who joined the faculty in 2023. Other former students include the pianists HaeSun Paik, Christopher Taylor and Christopher O’Riley.

In 1996, Mr. Sherman published“Piano Pieces,” a compilation of essays about teaching and performing. “Notes may be missed but not casually flubbed,” he wrote. “Phrases may be askew but not aimlessly drifting. Sonorities may be brazen but not barren. The player has to say something, with verve and style.”

In addition to his wife, survivors include his sons Edward and Mark, from his marriage to the pianist Natasha Koval, which ended in divorce, and several grandchildren.

“I think that musical performances should be free,” Mr. Sherman once said, and “should invite danger, should tell a story, should court the ‘madness of art,’ should in every way reveal the characteristics and visions of the composers.”

Reviewing Mr. Sherman’s performance of Prokofiev and Beethoven at age 17, the reviewer noted that “how individual a pianist he is remains to be seen,” but that the “searching way” he interpreted music boded well.

Mr. Sherman never abandoned that spirit of inquiry. According to his wife, when he was interviewed by the Nexus Institute in Amsterdam and asked what he wanted written on his tombstone, he replied: “A quest.”