A contemporary of Wilhelm Furtwangler and Otto Klemperer, and like them a conductor of 20th century music, Ansermet represents a very different tradition and approach. A native of the Romande region (French-speaking) of Switzerland, he was originally a mathematics professor who took to conducting locally. Travelling in France he met both Debussy and Ravel and consulted them on the performance of their works. During the First World War he met Stravinsky who was exiled in Switzerland, and began a lifelong association with Russian music.
In 1918 he founded his own orchestra, the Orchestre de la Suisse Romande. He travelled widely in Europe and America and became famous for accurate performances of difficult modern music, making first recordings of several works such as Stravinsky's Capriccio with the composer as soloist.
After World War II Ansermet and his orchestra rose to international prominence through a long-standing contract with Decca Records, and between then and his death he recorded most of his repertoire, often two or three times. His interpretations were widely regarded as admirably clear and authoritative, though they were not without their detractors, and differed notably from those of othetr famous 20th century specialists, notably Pierre Monteux and Stravinsky himself. Ansermet disapproved of Stravinsky's practice of revising his works and always played the original versions. Although famous for performing much modern music by other composers such as Arthur Honegger and Frank Martin, he avoided altogether the music of Arnold Schoenberg and his associates, even writing a long book (Les Fondaments de la Musique dans la Conscience Humaine) in which he sought to prove that Schoenberg's idiom was false and irrational.
Ansermet was an ardent man who argued his opinions vehemently. He was notable in Britain for his argumentative rehearsals with British orchestras, who were used to the more jovial style of Thomas Beecham and Adrian Boult. His last recording, typically of Stravinsky's Firebird, was made in London with the New Philharmonia Orchestra, and a recording of the rehearsals and sessions was made as a memorial to him.