Sankaku Channel/hatsune miku no shoushitsu (vocaloid)

http://vocaloid.wikia.com/wiki/Miku_Hatsune#Hatsune_Miku_no_Shoushitsu_.28The_Disappearance_of_Hatsune_Miku.29

A song about Miku if she reached the end of her life due to a virus that she has obtained. It dwells on her wish to be like a human and how she sees herself as just a toy for singing. At the same time, however, she still wishes to sing more and be together with her friends, but at the end her wish comes true. Much of the song is played at a super-fast rate so that the lyrics are barely distinguishable and almost (if not) humanly impossible to sing.
Multiple PVs exist for Hatsune Miku no Shoushitsu. Many of them approach the 'story' in a different way; one of the more popular interpretations is that the song is Miku's thought process as she is deleted from her master's computer. Other variations on the theme, however, do exist.