Final answer:
During Beethoven's middle period, one event that allowed him more artistic freedom was the rise of the middle class and the change in the audience for classical music.
Step-by-step explanation:
One event that allowed Beethoven more artistic freedom during his middle period was the rise of the middle class and the change in the audience for classical music. Unlike other composers who relied on the patronage of the aristocracy, Beethoven was able to write for larger audiences of paying customers who had less knowledge about music. This gave him the opportunity to experiment with new musical styles and push the boundaries of what was considered acceptable at the time.