He also continued another trend—towards larger orchestras—that moved the centre of the sound downwards in the orchestra, to the violas and the lower register of the violins and cellos, giving his music a heavier and darker feel than Haydn or Mozart. Gustav Mahler modified the orchestration of some of Beethoven's music—most notably the 3rd and 9th symphonies—with the idea of more accurately expressing Beethoven's intent in an orchestra that had grown so much larger than the one Beethoven used: for example, doubling woodwind parts to compensate for the fact that a modern orchestra has so many more strings than Beethoven's orchestra did. Needless to say, these efforts remain controversial.