What is the fine-grained topic of the following text: A trendsetter and also a trend enhancer, with an unmatched ability for capturing the zeitgeist with her music, Madonna has long been a figurehead for female empowerment, fearless in the themes she tackles in her songs, and as she has recently proved with her outspoken speech about ageism, still willing and able to spark debate on uncomfortable subjects. Only return the topic.
Madonna's influence on music and social issues.