A demo of Mindbender (Confusion's Prince) was recorded by the Grateful Dead (as The Emergency Crew) in November 1965. This is the version that is included on all of the releases listed below.
The song was performed a few times by the Grateful Dead in the first half of 1966.
The song was played by Phil Lesh & Friends in January 2015.
Grateful Dead
The Golden Road (1965-1973), 2001 The Birth Of The Dead, 2003 Birth Of The Dead, Vol 1 (The Studio Sessions), 2013 Complete Studio Rarities Collection, 2013