Lex van Delden was born Alexander Zwaap on September 10, 1919 in Amsterdam the only child of Wolf Zwaap, a school teacher, and Sara Olivier. After the war, Alexander Zwaap changed his name to Lex van Delden, which is a derivation of the name he used while he went into hiding during war. He died on July 1, 1988.
He began taking piano lessons from an early age - first from Martha Zwaga and later from Cor de Groot. He started composing at the age of eleven, when a long illness prevented him from playing the piano, and remained self-taught as a composer. Despite his artistic promise and interests he enrolled at the University of Amsterdam in 1938 to study medicine.
Between 1947 and 1982, Lex van Delden was the music editor of the daily newspaper "Het Parool". His social commitment was borne out by his readiness to hold several administrative posts, including the presidency of the Society of Dutch Composers (GeNeCo) and the chairmanship of the Performing Right Organization (BUMA/STEMRA).
He also sat on the Board of the International Society for Contemporary Music (ISCM) and was a member of the Dutch Committee of the International Music Council (UNESCO).
Still a student, Lex made his professional début as a composer in 1940 with the song cycle ‘L’amour' (1939), for soprano, flute, clarinet and string trio.
He was composer and musical director of the first post-war ballet company “Op Vrije Voeten” (later “Scapino Ballet”) since 1945.
The first of his works to attract wide attention was ‘Rubáiyát’ (1948), for soprano, tenor, choir, 2 pianos and percussion.
Many of Van Delden's compositions form an expression of his deeply felt social concern, such as ‘In Memoriam’ (1953), for orchestra, which was written in the aftermath of the great flood disaster of 1953, the radiophonic oratorio ‘Icarus’ (1962), which questions the usefulness of space travel, or ‘Canto della Guerra’ (1967) after Erasmus, for choir and orchestra, which is a strong condemnation of war. A number of his works have biblical themes, notably ‘Judith’ (1950), a dance score for flute, clarinet, piano and string trio.
The 'Sestetto per archi’ (1971) turned out to be a surprising musical strongly worded statement, with influences of Dmitri Shostakovich.
In 1948, he was awarded the Amsterdam Muziekprijs (Music Prize of the City of Amsterdam) for ‘Rubáiyát’. He received two First Prizes from the Northern California Harpists' Association: in 1953 for his ‘Harp concerto’ (1951) and in 1956 for his ‘Impromptu’ for harp solo (1955).
Lex van Delden received the “Speld van Verdienste” of the City of Amsterdam in 1982.