Final answer:
Amy Beach challenged the 19th-century social convention by becoming a successful composer and pianist in the male-dominated field of classical music, defying Victorian gender roles.
Step-by-step explanation:
In the 19th century, Amy Beach bucked the prevalent social convention which dictated that the composition and performance of classical music was an all-male profession. By establishing herself as a prominent composer and concert pianist, she navigated through the male-dominated sphere of classical music, ultimately becoming the first successful American female composer of large-scale art music. Her career choices challenged the Victorian gender roles that survived into the century and defied the strict conventions that were confining women to certain societal roles and professions.