Wrong Singer

Well-known vocalist starts believing the adulation and becomes a hot house flower.  Says "I can't work under these conditions!  I'll be in my trailer!"  Rest of band padlocks his trailer door because they still need to make their property tax payments, so they hire a ringer who may or may not be a dead ringer for the original singer, a "Ringer Singer" to keep making music. Things sound just slightly "off" with Deep Purple, Iron Maiden, Van Halen, Chicago, The Doobie Brothers, Genesis, Jethro Tull and The Doors.