Sir Charles Mackerras

LONDON — Sir Charles Mackerras, a renowned conductor acknowledged as the leading exponent of Leos Janacek's operas, has died of cancer. He was 84.

Mackerras died Wednesday night in London, according to the management firm Askonas Holt.

In Britain, Mackerras was associated with English National Opera and the Royal Opera, was formerly principal conductor of Welsh National Opera and was principal conductor of the BBC Concert Orchestra.

At various times he also held conducting posts in Germany, Australia, the Czech Republic, the United States, Austria and France, and he made many highly regarded recordings.

"Charlie Mackerras' impact on the development of musical performance practice over the last 60 years has been enormous," Royal Opera music director Antonio Pappano said.

"He was a force of nature, a true man of the theater, who grappled with how to honor a composer's intentions with the utmost rhythmic flair, drama and enthusiasm."

Mackerras made his last appearance at the Royal Opera House conducting Janacek's "The Cunning Little Vixen," which the house staged at his request.

The conductor did pioneering work on historic performance practices. An early result was his 1959 recording of Handel's "Water Music," which challenged the then-conventional lush performances by using the forces Handel had in mind, including 24 oboes.

"We got every wind player in London to come for one session, in the middle of the night, and have a go at it," Mackerras recalled.

"It was all edited and issued very quickly, in just a few days, and I must say I was a bit frightened that it would sound horrible, but of course just the opposite occurred. It sounded marvelous."

Mackerras brought the insights of the authentic performance movement to his conducting, notably in his work on Mozart's music and music of the baroque.

Born in Schenectady, N.Y., to Australian parents, Mackerras grew up in Australia and studied oboe, piano and composition at the New South Wales Conservatorium of Music in Sydney.

In 1947, he won a British Council Scholarship to study conducting with Vaclav Talich in Prague, which led to his enduring interest in Janacek.

Mackerras became fluent in Czech and prepared new editions of Janacek's scores.

He was principal guest conductor of the Czech Philharmonic Orchestra from 1997 to 2003.

He made his debut at the Metropolitan Opera in New York in 1972 leading Gluck's "Orfeo et Euridice," and the following year he conducted the opening performance at the Sydney Opera House.

Mackerras was knighted in 1979 and made a Companion of Honor — reserved for 65 living persons of distinction — in 2003.