This is the final song on Go!, and was one of my favourite songs to play over the years. It was a staple of nearly every live incarnation of Ganglion. There are probably more variations of it than of any other song in my repertoire.
Happened Happen Happen (Remix) Happened (Demo)
Original version, from Go!
From the Slake/Ganglion Split EP
Todo: Add other versions (Sghool, etc).