Simplify the following text for a Grade 7 native English-speaking person.
Original: The group were particularly famous between 1905 and 1920 , with RosÃ , Fischer , Ruzitska , and Buxbaum .
Simplified: The group 's peak period was between 1905 and 1920 , with RosÃ , Fischer , Ruzitska , and Buxbaum .