Answer:
Areas of real beauty - this case of inspirational content can most frequently be observed in the work of naturalist-artists, and the impressionists. Large aspects of water such as seas and rivers are especially preferred.
2) Notable others - the notable others of experts have highlighted prominently in art, both in traditional art and more recent works. To see how these people who profoundly affected the lives of others are recreated as a muse is incredibly interesting.
3) Current events - Artists often aim to follow political events or circumstances that are occurring right now in the world, so as to add their own voice and scene into the conversation.
4) Self-portraits - It's always interesting to see how any individual views themselves, especially when their musical talent enables us to see not only their view of themselves but to reconsider how we view ourselves.