Willem Mengelberg was a Dutch conductor known for his expressive and romantic style. He was also an advocate for new music and a highly respected interpreter of Mahler.

He was born on March 28, 1871, in Utrecht, the Netherlands, to German parents and was the fourth oldest of his 14 siblings. His father was a very successful sculptor and architect who specialized in furniture and interior design for churches. Mengelberg received his first musical instruction in Utrecht from Richard Hol, Henri Wilhelm Petri, and Anton Averkamp. This was followed by studies with Franz Wullner, Adolf Jensen, and Isidor Seiss at the Cologne Conservatory. His first professional appointment began in 1891 as the General Music Director for Lucerne, Switzerland. In this capacity, he was responsible for conducting and managing the music school, and he gave piano lessons. In 1895 he was asked to lead the Concertgebouw Orchestra as the principal conductor, a post that he ultimately held until 1945. Additionally, he was the chief conductor for the Amsterdam Toonkunst Choir, and in 1899 he began the annual tradition of performing Bach's St. Matthew Passion in a collaboration with both the choir and the Concertgebouw Orchestra.

Mengelberg, with the Concertgebouw, became a favored interpreter of composer Richard Strauss, who dedicated Ein Heldenleben to them in 1898. Strauss also claimed to have been inspired by the orchestra, freeing him from the fear of composing challenging music. Gustav Mahler also took notice and eventually befriended Mengelberg in 1902, which led to Mahler conducting the orchestra on many occasions. Conversely, Mengelberg also gained the reputation as one of the most respected interpreters of Mahler's music. From 1907 to 1920, he directed the Frankfurt Museum concerts, and in 1921 became the conductor of the New York International Symphony Orchestra, which lasted until 1929. He also conducted the New York Philharmonic starting in 1922 but left in 1929 due to creative differences with Arturo Toscanini, who was co-conductor at the time.

Mengelberg enjoyed performing new music and conducted world premieres of some of the most significant composers including Paul Hindemith, Darius Milhaud, Béla Bartók, and many others. However, his career suffered in the 1940s due to his unfortunate support for the Nazis in World War II. After the war ended in 1945, he was banned from performing in the Netherlands, putting an end to his time with the Concertgebouw Orchestra, and his recording career. He was exiled and he retreated to Switzerland, where he stayed in retirement until his death in 1951. ~ RJ Lambert, Rovi