Rebekah likes to be able to provide pretty much anything requested and sometimes at Sweet 16 parties I cringe when she does it....But on all of these streaming stuff - I quite frankly don't have a problem with not having someone request. Obviously you need a competent base of music. But I never make any claim to have every song ever made. If I don't have somebody's obscure country request... it makes my life a little easier in saying no to playing it.
My thinking is if you haven't previewed the song you have no clue the content and I don't want anything profane or explicit being played. Even on DJ pools, I have downloaded "Clean" versions which have words that I wouldn't call clean....