The soundtrack in Tarantino's 'Pulp Fiction' is a major part of what makes the film so memorable. Tarantino has a knack for choosing music that complements the action on screen. The music ranges from classic 60s soul to more obscure tracks. It not only sets the time period but also the mood of the characters. For instance, the use of Chuck Berry's 'You Never Can Tell' in the dance scene at Jack Rabbit Slim's is pure genius. It makes the scene both fun and slightly off - kilter, which is typical of the film as a whole.
They might be really excited. The characters in RWBY are often associated with great music in their own show. They could be impressed by how a fanfic uses the concept of the soundtrack to create a new story. For example, if the fanfic focuses on a particular emotional song from RWBY's soundtrack and builds a story around the feelings that song evokes, the characters might feel a strong connection to it.