Conductor Willem Mengelberg (1871-1951) was a stimulating force in the musical life of the Netherlands at the beginning of the 20th century. As conductor of the Concertgebouw Orchestra, he transformed Amsterdam into a capital of the musical world. His famed interpretations of works by Richard Strauss, by J.S. Bach (St Matthew Passion) and of the music by Gustav Mahler was acclaimed internationally. For many conductors, Mengelberg established an international standard of orchestral performance. Innumerable musicians around the world admired Mengelberg for his peerless interpretations. His introduction to Mahler’s Third Symphony in 1902, in Krefeld, Germany, was both lasting and decisive for Mengelberg’s artistic development. His intense interest in the music of his composing contemporaries never became comparable to his lifelong devotion to music by Mahler, with perhaps the sole exception of Strauss. On many occasions, Mengelberg characterised Mahler as ‘the Beethoven of our time’. This deeply sincere fascination never vanished. Consequently, Mengelberg developed a legendary Mahler tradition in Amsterdam. One of the first recordings in the history of the Concertgebouw Orchestra was the Adagietto from Mahler’s Fifth Symphony (performed 39 times as part of the entire symphony, but as many times as a separate piece too). In 1947, Mengelberg qualified the early Columbia release included here as his best recording ever. He performed Mahler’s Fourth Symphony in The Netherlands 112 times. The live recording of November 1939 is a famous one, in part due to the remarkable rallentando in the opening bars. It is important to realise, however, that this rallentando was made during a live performance, spontaneously, originating from the conductor’s cherished ideas on improvisando, the spontaneous musical idea born in the moment. He conducted the Lieder eines fahrenden Gesellen only thirteen times, including six featuring baritone Hermann Schey. One of these performances, also from November 1939, was broadcast live on the radio. A music critic noted that the orchestra had that typical Mengelberg-Mahler sound during the performance.