Soap operas refer to TV shows, often during the daytime, with a continuing plot and characters. In the first days of television in the U.S., such soap operas were usually watched by housewives during the day. The advertisements were created with these women in mind and featured jingles (songs) with some catchy tune that would be remembered and thus associated with the products, at least in the minds of the people watching. They still use jingles in advertisements, but not as much as in former times.

It sounds to me like someone who offers creative input into a 'soap opera' on TV. A soap opera is a long-running TV serial about ordinary life like 'Coronation Street'. http://www.itv.com/coronationstreet/