Marion Thorpe: Pianist who fled the Nazis in 1938 before sacrificing her career for her family and going on to marry Jeremy Thorpe

Marion Thorpe maintained an elegant passage through life despite enduring more than her fair share of vicissitudes, none of her own making. Every one of them sprang from the men in her life: her father, the music publisher Erwin Stein; her first husband, George Lascelles, 7th Earl of Harewood; and her second, the 1970s Liberal party leader Jeremy Thorpe.

In her twenties, having studied at the Royal College of Music, she became a noted concert pianist, was photographed by Cecil Beaton and was serenaded at her wedding to Harewood in September 1949 with an anthem specially composed by Benjamin Britten, who conducted the piece at the ceremony.

An acknowledged beauty, she shone in the surge to restore music and the arts in Britain in the 1950s after the Second World War. She had suffered from that time more sorely than many of her audiences: at the age of 12 she had been torn from her home in Vienna in 1938 because her father was Jewish, and the family, obliged to flee the Nazis, settled in London. There Erwin Stein took a job with the music publisher Boosey and Hawkes and became an early mentor of Britten, then a rising star.

Her Viennese curtsey to Britten, charming him on her first meeting with him, became a story often told, and she remained a friend of his, despite his notorious tendency suddenly to drop acquaintances, until his death in 1976. It was through Britten, at the first of his festivals at Aldeburgh in Suffolk in 1948, that she met King George VI's musical nephew, George Lascelles, 11th in line to the throne and son of the king's sister, Princess Mary, and her husband Henry, the 6th Earl. They married at St Mark's Church, North Audley Street, Mayfair, the following year, and she became chatelaine of Harewood House, the Lascelles' magnificent pillared Georgian pile of more than 90 rooms near Leeds in West Yorkshire, built for Edwin Lascelles, a trader in the West Indies, in 1771.

She had become known for her performances of Mozart and Schubert pieces four-handed at one piano with the pianist Catherine Shanks, and she also played Bach and Mahler. But she relegated the concert career to second fiddle in favour of raising her family. She had three sons, and the music burst forth in a new direction. She engaged as their piano tutor the distinguished music teacher Fanny Waterman (now a Dame). The two shared not only their musicianship but a background of emigration from elsewhere: Waterman was the daughter of another Jewish refugee, her father, Myer Waterman, having come from Russia.

Shared interests sparked ideas, and gave rise in 1963 to the Leeds International Piano Competition, of which winners have included Radu Lupu and Murray Perahia. The competition takes place, as did an older Leeds Festival from 1874, every three years, and before it would next be staged, in 1966, Marion's world was to crumble for a second time in her life. By then her marriage had broken down. Lascelles had an affair with, and would later marry, Patricia Tuckwell, with whom he had a child, and in 1967 Marion at last agreed to a divorce.

The music, however, went on. With Fanny Waterman she produced a series of piano lesson-books, "Me and My Piano", that proved popular and have sold millions of copies.

Musical circles overlapped with political ones. Among those who moved in both was the pianist (later Dame) Moura Lympany, who is said to have introduced Marion in the early 1970s to the dashingly handsome violinist who happened to be leader of the Liberal Party, Jeremy Thorpe. The Eton- and Trinity College, Oxford-educated Thorpe, who took over the party from Jo Grimond in 1967, and was MP for North Devon, had been left a widower with one son after his first wife, Caroline Allpass, died in 1970 in a car accident.

Marion married Jeremy Thorpe at Paddington Register Office in February 1973, and campaigned with him in the Election of February 1974, which gave rise to a hung Parliament in which Thorpe held a pivotal place. He refused to join the government of the Conservative Edward Heath as Home Secretary, and a second election in October that year gave Labour under Harold Wilson a slender majority.

Her great gift to Thorpe over the turbulent years that followed, through his fall from public life, and his three decades darkened by illness, was her loyalty. No matter what might be said by those who opposed him, posterity must surely record that it says something for the quality of a man that he had such a wife.

The trial for attempted murder in 1976 of Andrew Newton, a former airline pilot, began a chain of events that brought Thorpe's career crashing down. Newton had shot and killed a great dane, Rinka, belonging to a male model called Norman Scott. Scott alleged that Thorpe had hired Newton to kill him in order to stop him revealing a homosexual affair in the 1960s – when such an affair could have attracted a criminal prosecution. Thorpe denied the affair, and was cleared of conspiracy to murder in 1979, but lost the party leadership and his North Devon seat. Three years later he was diagnosed with Parkinson's disease, and Marion devoted herself to his care.

ANNE KELENY

Maria Donata Nanetta Paulina Gustava Ermina Wilhelmina Stein, pianist: born Vienna 18 October 1926; CBE 2008; married 1949 Earl of Harewood (divorced 1967; three sons), 1973 Jeremy Thorpe (one stepson); died Cobbaton, Devon 6 March 2014.