The term “music producer” can mean a number of things and can involve a plethora of tasks from audio engineering, the songwriting consultation, to mixing and mastering the audio. It’s essential that the invoice delineate precisely the what services were provided and the cost of each. Any equipment or studio rental should also be defined within the invoice. Generally speaking, the invoice will be sent to the client following the delivery of the final masters indicating the date by which the musician/band/label must pay.