As a producer in the Music Business you will be responsible for the entire project. Possibly the single most important job function you perform is to elicit the best performance out of the recording talent.
As, well you will coordinate the recording session, assist in the arrangement of the music piece, eliminate unnecessary sections of a song, alter the instrumentation within the song, and make important decisions that reflect the image of the artist. Although, this term is widely overused, most great producers have been in the music business for many, many years bringing their vast array of experience to the table.
If you have never done any serious musical productions with success, refrain from using this term when applying for a job. Most employers will not take you serious if you do.
This can be one individual or an entire group of people who have the ultimate decision regarding the direction of a musical project. Usually, they are the ones who provide the financing.