根据所给的中文完成句子。
1. 他写了400多首华尔兹。
He wrote _____ _____ 400 waltzes.
2. 施特劳斯和莫扎特是两位最重要的作曲家。
Strauss and Mozart were _____ _____ _____ _____ important composers.
3. 在他6岁前不仅弹钢琴,而且还拉小提琴。
Before six, he played _____ _____ the piano, _____ _____ the violin.
4. 他在很多城市开音乐会。
He _____ _____ in many cities.
5. 施特劳斯写哪种音乐?
_____ _____ music did Johann Strauss write?
6. 除了戏剧外,莫扎特还写了什么?
What did Mozart write _____ _____ _____ operas?