Thomas Dunn, 82; artist of music led the Handel and Haydn Society in Boston

Mr. Dunn led a Handel and Haydn Society rehearsal in 1979.

Three hundred years after the birth of Johann Sebastian Bach, Thomas Dunn led the Handel and Haydn Society through a warm-up of the composer's B-Minor Mass, and then paused in Symphony Hall as chorus, orchestra, and soloists prepared for the evening's concert.

"Just as we finished, before he stepped off the podium, he said to us, 'And remember whose birthday it is,' " John Finney, now associate conductor and chorusmaster of the society, said of that anniversary concert in Boston in 1985. "He looked up toward heaven and said, 'Just let him hear it.' "

For audiences celestial and mortal, Mr. Dunn coaxed stellar performances from the Handel and Haydn Society during 19 years as artistic director, including each December's presentation of Handel's "Messiah."

Mr. Dunn died of heart failure Sunday in Bloomington Hospital in Bloomington, Ind., where he had taught for several years at Indiana University's Jacobs School of Music.

He was 82.

As the hand that held the baton for a storied Boston performing group that was founded in 1815, he was a key figure in the city's classical music scene, from his appointment in 1967 to his retirement as conductor laureate in 1986.

"Mr. Dunn was a visionary artist and conductor who transformed the organization, and his legacy profoundly impacted the society," the Handel and Haydn Society said in a statement. "He led the society in no less than 160 performances, bringing a uniquely personal artistic statement to every musical endeavor. Under his guidance, the society became a fully professional organization with a broad and varied repertory."

The society is dedicating its December performances of the "Messiah" and its Bach Christmas performances to Mr. Dunn.

"One of the most extraordinary things about Tom was his extremely generous spirit," said David Manuel Villanueva, Mr. Dunn's partner of 30 years. "I think that's one of the things that made him a fabulous conductor and such a great teacher to so many generations of musicians."

Finney, who will direct the society's chorus for the December concerts, called Mr. Dunn "a musician of the highest integrity."

"He took responsibility for every bowing in every string part, for every articulation in every choral part," Finney said.

From the late 1970s until Mr. Dunn retired as artistic director, Finney was the pianist for the society's chorus rehearsals.

"I remember every one," he said. "It was like watching a fine craftsman refine a diamond, taking this very, very beautiful work and making it more and more beautiful, shaping every word, every phrase the chorus sang."

That craftsmanship was honed at an early age. Born in Aberdeen, S.D., Thomas Burt Dunn grew up in Baltimore, where he attended the Peabody Institute, a music conservatory that is now part of Johns Hopkins University.

At 11, he became assistant organist at Third Lutheran Church in Baltimore, but music had held his undivided attention from when he was still in a crib, according to a 1963 profile in Time magazine: "To amuse him, his parents put a tall phonograph and a stack of symphony records within reach, and Baby Dunn would change the records."

He graduated in 1946 from Johns Hopkins and Peabody, where his teachers included organists E. Power Biggs and Virgil Fox. Mr. Dunn studied choral arranging at Harvard, from which he received a master's degree. Awarded a Fulbright scholarship, he continued his studies at Amsterdam Conservatory.

After several years as a church music director in Baltimore and Philadelphia, he moved to New York City in 1957 to become music director of the Church of the Incarnation. A successful series of concerts that Mr. Dunn organized led him to form the Festival Orchestra and Chorus.

Two years later, he was named conductor of the Cantata Singers in New York. As a conductor with that group, he made his Carnegie Hall debut in 1960.

Through the years, along with his conducting duties, Mr. Dunn served as editor of E.C. Schirmer music publishers, now based in Boston. Along with teaching at Peabody, he also taught at Boston University, Ithaca College, Stanford University, and at Westminster Choir College.

While building his reputation in New York City in the early 1960s, Mr. Dunn often was called a purist, a word that in music criticism can be either praise or a pejorative.

"I rather like the word," Mr. Dunn told the Globe in 1967, when he was appointed artistic director of the Handel and Haydn Society, adding cheerfully in a separate interview, "I should certainly hate to be in the opposite camp of the impurists."

In a letter to the Globe, published in 1965, he had explained some philosophical underpinnings of his conducting that delighted many listeners and bedeviled a few, too.

"Handel was a genius among giants in the art of orchestration, the equal of Haydn or Mozart or Stravinsky," he wrote. "To disturb the proportions of his instrumentation by so much as two violins or one bassoon is to obliterate the wonderful subtleties of sound that are nowhere to be found on the printed page, but are wondrous in the ear!"

As for the "Messiah," the signature Christmas season event for many audiences, Mr. Dunn found a way to stay fresh after years of conducting performances.

"It's a strange thing," he told the Globe in 1983. "One does sort of dread, in between times, having to do it, but the minute you start rehearsing, it all comes to life again. About every five years or so I throw away my score and buy a new one and start as if I've never seen the piece before."

In addition to Villanueva, Mr. Dunn leaves a nephew and three nieces.

A memorial service will be held at 2 p.m. Saturday, in Trinity Episcopal Church in Bloomington, Ind. Burial will be in the family plot at Green Mount Cemetery in Baltimore. A service in Baltimore will be announced.