Richard Hickox, described as "one of the world's leading conductors", has died from a suspected heart attack aged 60.
Hickox died on Sunday in his hotel room in Cardiff after a recording session in the city, his publicist said. He was due to conduct English National Opera's new production of Vaughan Williams's opera Riders To The Sea, opening this Thursday.
The conductor is survived by his wife, the mezzo-soprano Pamela Helen Stephen, and his three children, Tom, Adam and Abigail.
Hickox was musical director of Opera Australia, associate guest conductor of the London Symphony Orchestra, founder and music director of the City of London Sinfonia, co-director of the period instrument group Collegium Musicum 90 and conductor emeritus of the BBC National Orchestra of Wales.
Stephen Lumsden, managing director of Intermusica, and Hickox's agent for more than 20 years, said: "The shock of Richard Hickox's sudden and unexpected death will resonate right around the globe and has robbed the music world of one of its most popular and respected musicians.
"It also takes away from his beloved family a deeply devoted husband, father, son and brother.
"Literally thousands of musicians who were touched by his talent, energy and that remarkable generosity of spirit of his will feel that loss as well.
"Richard never wavered or faltered in his commitment and support for others, even when faced with the most daunting challenges.
"His ability to inspire the best through his passion for the music he conducted created countless memorable performances in the concert hall, on the opera stage and on disc.
"His championing of British music and his international successes, particularly in Sydney, as well as his legacy of hundreds of recordings across the whole spectrum of repertoire will remain for many years to come.
"All those who knew him will feel deeply for his wife Pamela and his three children, to whom we offer our most sincere and heartfelt condolences."