It's 1957 and Ed Gein has just been arrested after committing his second murder. Through a series of flashbacks and imagined memories we see Ed's story through his own eyes while hearing his story through parodies of classic songs.
After his mother dies, Ed finally goes completely off the deep end, digging up recently deceased females to be his "girlfriends" and using their remains for whatever he sees fit, singing his way through the corpses and eventual murders. Once Ed's deeds are finally found out, the sheriff and his deputies must sort through the wreckage of this unreliable narrator.
As a treatise on "crazy" and a twisted romp through Ed's imagination, Ed Gein: the Musical manages to be both a wild fantasy and a fairly historically accurate film about Ed's crimes and capture.