For example, consider William Shakespeare: "To be or not to be?" He was very much a popular entertainer, but his work had depth. Also consider Samuel L. Clemens, he tried to shock and provoke introspection, but was also very much a popular entertainer. His work, "The Mysterious Stranger" ended in a sharp note on pondering the nature of existence.
Looking here for more such examples/whatever can be legally quoted or paraphrased.