Short answers, pulled from the story.
According to the United States Employment Service, a musician is a person who follows music as a profession. The term is considered a general designation that covers composers, conductors, performers, and songwriters.
A composer is a specific type of musician who creates musical compositions, principally for classical music, film music, theatrical stage productions, or video games. A musician who records and releases music more broadly is typically called a recording artist rather than a composer.
A conductor directs the simultaneous performance of several players or singers through gesture and eye contact while standing on a raised podium. Conducting has been defined as an art form distinct from playing an instrument, as the conductor produces no sound directly.
Singer and vocalist refer to the same role; vocalist is an alternative term for a performer who provides vocals. Both words describe a music performer who uses their voice rather than a musical instrument as their primary medium.
A musician's output is influenced by culture, skill set, life experience, education, and creative preferences. These factors shape not just the style of music a musician produces but also the genres they work in and the creative choices they make.
A music producer is not a musician outright, but may themselves be a musician. Producers shape the sound of an album or song, oversee the recording process, and guide creative direction, often collaborating with artists, musicians, and sound engineers.