We talk about a “song” at least two different ways. The first is as a musical work, an abstract entity that serves as an umbrella for many versions or renditions. In most cases a song’s title marks it as being the “same” in all its various versions, although occasionally the same song acquires different titles and gains or loses lyrics. Second, we conceive of a song as a rendition, that is, a realization of the song in a performance, a publication, or a recording. Each rendition of a song is unique, although renditions may be very similar to one another.