sentences:  After leaving for Prague in September 1857, Dvořák entered the city's Organ School, studying singing with Josef Zvonař, theory with František Blažek, and organ with Joseph Foerster.The latter was not only a professor at the Prague Conservatory, but also a composer for the organ; his son Josef Bohuslav Foerster became a better known composer.Dvořák also took an additional language course to improve his German and worked as an "extra" violist in numerous bands and orchestras, including the orchestra of the St. Cecilia Society.