Sentence:  But musical ancestry aside, the influence to which Bieber is most <WSD>beholden</WSD> is the current trends in pop music, which means Believe is loaded up with EDM accouterments [sic], seeking a comfortable middle ground where Bieber's impressively refined pop-R&B croon can rub up on techno blasts and garish dubstep drops (and occasionally grind on some AutoTune, not necessarily because it needs it, but because a certain amount of robo-voice is expected these days). 
Meaning of the word marked with <WSD> tags:  Bound by external expectations, such as fashion or morality.