“We could leave the Christmas lights up 'til January” - that lyrics always bugged me when it came on the radio. Christmas ends on 5th January (12th day of Christmas), so the Christmas lights are meant to still be up in January!
Given that the top 8 non-featured songs with the tag "specific musical act" are all about her songs, I would say that they get featured a reasonable amount. The problem (if it is one) is with users preferences and the choice of which artists they want to take quizzes about.
Might as well continue listen to Indie and Rock
(: