Zoltán Kocsis, who has died aged 64 following a long illness, was a member of a distinguished troika of Hungarian pianists – with Dezsö Ránki and András Schiff – who emanated from the late 1960s class of Pál Kadosa at the Liszt Academy of Music in Budapest. Schiff, although the youngest of the trio, was the first to embark on an international career, while Kocsis, like Ránki, remained closer to Hungary, engaging fruitfully with his compatriots, provocatively and often courageously towards officialdom. Kocsis’s contribution to the culture of his native country was all the more valuable in that he was not only a pianist and conductor, but also a teacher, arranger, musicologist, composer, record producer and critic.

Underpinning that versatility was a sense of mission: a burning desire to pass on the insights and experience of previous generations. To that end he would proselytise on behalf of, for example, Rachmaninov’s or Bartók’s performances of their own works, even when this approach ran counter to orthodoxy. Thus his interpretations of Bartók (he recorded the complete piano works, both solo and with orchestra, to high acclaim) exemplified his conviction that the “barbarism” traditionally projected in the ubiquitous motor rhythms was too extreme, too mechanical. Kocsis preferred a more flexible and sensitive approach, as had been demonstrated, he maintained, by Bartók himself.

Rubato was indeed a prominent feature of all Kocsis’s playing, whether in his ravishing account of Grieg’s Erotik, in the subtle inflections of Debussy’s Clair de Lune, evoking the preternatural stillness of a moonlit night, or in the transcendental figuration of Liszt’s Les Jeux d’Eaux à la Villa d’Este. The other predominant characteristic of his performances was the pellucid tone, consistently sensuous even in passages of heightened emotion and enhanced by the singing quality he unfailingly brought to melodic lines.

As a conductor, Kocsis achieved prominence as co-founder with Iván Fischer of the Budapest Festival Orchestra in 1983. Remaining as an artistic director until 1997, he helped establish the orchestra as one of the leading world ensembles, with appearances at the Amsterdam Concertgebouw, Vienna Musikverein, BBC Proms and Salzburg and Lucerne festivals. In 1997 he became music director of the Hungarian National Philharmonic Orchestra, nailing his colours to the mast with a performance of Schoenberg’s massive Gurrelieder in his first season. Inventive programming and contemporary repertoire remained features of his orchestral and solo piano programmes: among the composers who wrote works for him was György Kurtág, another of his teachers at the Liszt academy.

Born in Budapest, son of Mária (nee Mátyás) and Ottó Kocsis, Zoltán began his piano studies at the age of five and continued them at the Béla Bartók Conservatory, where he also learned composition. Moving on to the Liszt Academy in 1968, he was still a student when he won the Hungarian Radio Beethoven Competition in 1970. The following year he toured the US, and in 1972 appeared in London and at the Salzburg and Holland festivals. Rapidly establishing a career as an international pianist, he also achieved celebrity status in Hungary, as conductor and teacher as well as pianist. His academic pursuits continued to inform his activities on all fronts: meticulous in his study of texts and sources, he brought a scholarly, inquiring mind to the art of performance. He was appointed to teach at the Liszt academy in 1976.

Dividing his time between playing and conducting, he appeared with leading orchestras such as the Berlin Philharmonic and Royal Concertgebouw, as well as the Hungarian National Philharmonic. He also toured extensively in Europe, America and the Far East.

With his cherubic features, shock of wavy hair and penetrating, often idiosyncratic, readings, he had a charismatic stage presence, and was especially renowned for his exceptional pianistic talents, on account of a series of prizewinning recordings. In addition to the complete Bartók series, he made some acclaimed recordings of Debussy, Rachmaninov, Liszt and Dohnányi. Drawing on his talents as composer and arranger, he made his own version of Rachmaninov’s Vocalise, concluding with imaginatively virtuosic figuration.

His transcription of the Prelude to Wagner’s Tristan und Isolde, which at the climax spills on to multiple staves, deployed virtuosity to project the heights of passion. It is possible to feel that his account of the Liebestod from the same work (this time using Liszt’s version) emphasised passion at the cost of Isolde’s transfiguration; a similar criticism may be levelled at his forceful rather than enraptured Prelude to Lohengrin. Elsewhere, however, his undoubted virtuosity was harnessed to a sensitivity and poetic imagination that made his artistry compelling.

In 1986 he married the pianist Adrienne Hauser. After their divorce, in 1997 he married the pianist Erika Tóth. She survives him, as do their son, Krisztian, also a pianist, and daughter, Viktoria, and his son, Mark, and daughter, Rita, from his first marriage.

• Zoltán Kocsis, pianist and conductor, born 30 May 1952; died 6 November 2016