Assertion: riff | /r/HasProperty | main theme
Facets:
value: for a song
type: PURPOSE
Source sentences:
text: Because a riff is a main theme for a song, it often becomes inextricably associated with that song---if you heard the riff out of context (say, someone trying out guitars in Guitar Center), you'd associate it with the song.
text: Riff is one of the main characters in The Ghost of Faffner Hall.