 Throughout Buffy the Vampire Slayer , music serves as a narrative tool , integral to character development and action . The mood is set by music , characters discuss it , and writers use it to emphasize differences between generations . In an essay on the use of music in the series , Jacqueline Bach writes that in conjunction with the sixth season themes of growing up , " Once More , with Feeling " gives music a central role instead of keeping it in the background . 
