"Inní mér syngur vitleysingur" (Icelandic for "Within me a lunatic sings"[1]) is the second track on Sigur Rós' fifth album, Með suð í eyrum við spilum endalaust. It is the first single from the album and was released on 8 September 2008.[2]
A music video for "Inní mér syngur vitleysingur" was also released. It shows the band playing at the free Náttúra (Nature) concert in Reykjavík on 28 June 2008.[3]
Vocals from this track were sampled by the experimental electronic duo, Crystal Castles, in the song "Year of Silence", on their second self-titled release Crystal Castles.