Gustave Adolph Kerker (1840–1923) was a German-American composer and conductor, primarily recognized for his contributions to the operatic and musical theatre genres. Born in Germany, he emigrated to the United States in the mid-19th century, where he became a prominent figure in the development of American musical theatre. Kerker is best known for his operas and operettas, with notable works including "The Black Hussar" (1881) and "The Fortune Teller" (1898), which showcased his ability to blend European operatic traditions with American musical styles. His music often featured memorable melodies and engaging narratives, appealing to the popular tastes of his time. Kerker's impact on music lies in his role as a bridge between European classical traditions and the burgeoning American musical landscape. He contributed to the establishment of a distinct American voice in musical theatre, paving the way for future composers. His works were performed widely in the late 19th and early 20th centuries, influencing the development of American operetta and musical comedy. Despite being less recognized today, his contributions remain an important part of the history of American music.