Could anyone help me understand the idiom "to define the franchise" ? Emotion: smile As in the sentence:

"It has been a few years since Klaus' large-scale score to "Pirates of the Caribbean" defined the franchise and brought him worldwide mass attention."

I'll appreciate any help Emotion: smile
I guess it means that his music became the 'theme song', the recognizable music, of the Pirates series.
Thank you, Mister Micawber. I thought that it could mean "he (the composer) defined his brand" or so (an obvious nonsense), but since it's certainly a reference to the whole series, the phrase is probabely to mean that his score had a defining impact on sequels' soundtracks and the entire feel of the "franchise"... Thanks a lot.