MORE MONKEES

Next to his appearance in the 1968 "Head" movie, Frank Zappa was also featured in one of The Monkees' TV Shows.
In show no. 57, broadcast on March 11, 1968, Michael Nesmith teaches Frank Zappa how to play a car to the tune of The Mothers Of Invention’s ‘Mother People’.

This got released on :

• The Monkees: Vol. 16
      (1995, vhs video, USA, rhino home video)

And then there's the Davy Jones / Frank Zappa interview.
I don't know if this was also part of show no. 57, but it did find it's way to a Monkees DVD.

• The Monkees: Hey, Hey… We’re The Monkees
      (2005, dvd, Norway, scantrade entertainment)

Both fragments :