Werner von Trapp was probably best known to the world as “Kurt”, his fictional counterpart in the film The Sound of Music (1965).

The film and Broadway musical, which made von Trapp a household name, was loosely based on his step-mother's memoirs of the singing family's early years in Austria. The fourth child in a family of seven children, Werner von Trapp sang tenor in their choir, the Trapp Family Singers, which brought the family Europe-wide fame in 1935.

He was born in 1915 in the Alpine town of Zell am See. His mother, Agathe von Trapp, granddaughter of Robert Whitehead, the inventor of the torpedo, had fled from Pola where his father, Captain Georg von Trapp, a U-boat commander in the Imperial Austrian Navy, was stationed.

In 1922 von Trapp lost his mother to scarlet fever and in 1927 his father was married again, this time to his daughter Maria's governess, Fräulein Maria Kutschera, with whom he would have a further three children. She had been sent from the Benedictine Abbey of Nonnenberg in Salzburg, where she was intending to enter holy orders.

She taught the children (who could already sing) Austrian folk songs, Mozart, Bach and other church music. In the 1930s Werner von Trapp learnt to play the cello and other musical instruments.

When the family emigrated from Nazi-occupied Austria in 1938, they fled via Italy to the United States where they had a contract with a New York booking agent. The dirndl and lederhosen-clad children took New York concert audiences by storm. They later settled in rural, mountainous Vermont. Werner von Trapp volunteered for the US Army and fought in Italy for the US 10th Mountain Division.

Returning to the family farm after the war, he rejoined the choir. In 1959 the Broadway composer Richard Rodgers and the lyricist Oscar Hammerstein turned the family's life in Austria into the musical which would give it worldwide recognition. Songs from it are so firmly embedded in popular culture that one, Edelweiss, is sometimes mistaken for Austria's national anthem. Ever passionate about music, Werner von Trapp moved to Pennsylvania to help to found a music school called the Community School of Music, when the family choir was dissolved after 15 years. After a few years, however, he took to dairy farming back in Vermont, where he was to spend the rest of his life. He retired in 1979 and dedicated his energies to travel, spinning, crocheting and weaving.

Long after von Trapp stopped singing professionally he inspired four of his grandchildren from Montana to take up where he and his siblings left off. The new Trapp Family Singers were soon touring the country.

He is survived by his wife and six children and four of his singing siblings, three sisters and one brother.

Werner von Trapp, member of the famous musical family, was born on December 21, 1915. He died on October 11, 2007, aged 91