I know that the answer to the question "What determines the category?" is in "The "soft" AC format has reinvented in the late 2000s/early 2010s as a result of its declining relevance, adopting a more upmarket, middle-of-the-road approach, with a selection of "oldies" (usually from the 1960s/70s onwards), primarily rock, jazz, R&B and pop music. Newer songs are more often (but not limited to) "easy listening" fare, this amount varying depending on the age of the station's target demographic.". Can you tell me what it is?
The answer to this question is:
the age of the station's target demographic