Which term indicates a marked emphasis on a note or passage in music?

The term that indicates a marked emphasis on a note or passage in music is "marcato." This term comes from the Italian word meaning "marked," and it instructs the performer to play the indicated notes with a strong accent or a noticeable emphasis, creating a more pronounced sound. This emphasis can enhance the musical expression of a piece, drawing attention to certain notes or phrases and conveying a sense of urgency or importance.

The other terms provided refer to different musical concepts. "Ostinato" refers to a repeated musical phrase or rhythm that persists throughout a work or a section, often creating a foundation for variations above it. "Robusto" suggests a performance style that is strong and bold but does not specifically indicate emphasis on individual notes. "Doloroso," meaning sorrowful or mournful, pertains to the character or emotional quality of the music, rather than to the specific articulation of notes. Understanding these distinctions helps clarify why "marcato" is the appropriate choice for indicating marked emphasis.