Reporting income from similar streams of income can be reported on a single Schedule C. However, a musician would typically report income under NAICS Code 711110, while Independent Artists, which voice actors would be considered, typically report income under NAICS Code 711510. These two types of work are different enough to require separate Schedules C.
To confirm which codes are most appropriate for each of your streams of income, the NAICS Association's site would prove useful.
