Muck served as music director of the Boston Symphony Orchestra (BSO) from 1906 to 1908 and then again from 1912 to 1918 (with a yearly salary of 28,000 dollars as the "New York Times" reported on March 26, 1918). Initially he had to work to expand his repertoire from the operas and German music he concentrated on in Europe. Olin Downes later wrote that "his repertory was unequal to the demands of his audience" so he relied on members of the BSO for coaching in French works. Contemporary works were not his strong suit, though he dutifully programmed music that was not to his own taste, such as the American premiere of Schoenberg's "Five Pieces for Orchestra". He also introduced some Sibelius symphonies and many works of Debussy to Boston. Despite his restrained style, he occasionally revealed his romantic side in a work like Liszt's "Faust Symphony". On his death the "New York Times" said that in Boston "he built a virtuoso orchestra."