Several Species Of Small Furry Animals Gathered Together In A Cave And Grooving With A Pict - 2011 Remastered Version

This is Roger Waters' addition to Pink Floyd's ambitious album Ummagumma. One disc of the album is live performances of old songs, and the other is a composition from each member of the band.

The sounds of the "small furry animals" were actually created by Roger Waters and mixed in at varying speeds to make them sound somewhat realistic.

There is a hidden message at about 4:22 into the song. If played at a slower speed, you can hear a voice (most likely either Waters or guitarist David Gilmour) say, "That was pretty avant-garde, wasn't it?"