Complex sentence: Composer Friedrich Silcher was directly influenced by Pestalozzi and Nägeli; had been using large choirs to express political viewpoints since 1824 when he and a group of Tübingen University students performed La Marseillaise to commemorate the storming of the Bastille.
Split into simpler sentences: Composer Friedrich Silcher was directly influenced by Pestalozzi and Nägeli. He began using large choirs to express political viewpoints at least as early as 1824 when he and a group of Tübingen University students performed La Marseillaise to commemorate the storming of the Bastille.