Human: What are the main differences between a symphony and an opera? Assistant: 
The main difference between a symphony and an opera is that a symphony typically has multiple movements, while an opera generally has one or two. A symphony usually features a larger orchestra than an opera, with more instruments playing at once. An opera also tends to have a greater emphasis on vocal performances, such as singing and speaking. Additionally, a symphony will often include instrumental solos, whereas an opera may not. Lastly, a symphony is typically written for a full symphony orchestra, while an opera can be composed for any combination of singers, musicians, and dancers.