Final answer:
Beethoven and Mozart wrote duo sonatas that indeed treated the two instruments as nearly equal partners, which is true. During the Classical period, there was an emphasis on a balanced dialogue between instruments in compositions. Romantic era composers continued to use these classical forms while incorporating their own emotional expression.
Step-by-step explanation:
Beethoven and Mozart indeed wrote duo sonatas that treated the two instruments as nearly equal partners, which is true. This approach was a departure from the earlier Baroque practice where typically one instrument, often the keyboard, would dominate while the other, such as a violin, would have a more accompanying role. During the Classical period, new compositional practices emerged that favored a more balanced dialogue between instruments.
In the Romantic era, composers admired and were influenced by the works of Classical period composers like Haydn, Mozart, and particularly Beethoven. They retained the established forms and fundamental rules of Classical music while adding their own emotive expression and expanded technical demands. This included writing symphonies, concertos, sonatas, and operas with the same importance given to rhythm, melody, harmony, harmonic progression, tuning, and performance practice.