Robert "Bob" Marks is an American vocal coach, music arranger, accompanist, conductor, and music director in New York City. His students have included Natalie Portman, Britney Spears, Ariana Grande, Lea Michele, Laura Bell Bundy, Kerry Butler, Nikki M. James, Constantine Maroulis, Sarah Jessica Parker, Debbie Gibson, and Ashley Tisdale.]He is the co-author (with Dr. Elizabeth Gerbi) of "Bob Marks' 88 Keys to Successful Singing Performances: Audition Advice From One of America's Top Vocal Coaches," which was published by Thomas Noble Books in 2020.