Final answer:
Beethoven incorporated elements of classical music in his early period of writing music, including the popular forms and rules of the Classical period.
Step-by-step explanation:
In his early period of writing music, Beethoven incorporated elements of classical music. He continued to write symphonies, concertos, sonatas, and operas, which were popular forms among classical composers.
Beethoven also followed the rules of rhythm, melody, harmony, harmonic progression, tuning, and performance practice that were established in the Classical period.