he was not on the Johnny Cash because Johnny Cash show only ran from 1964 to 1971 but Elton John was on The Muppet Show
It appears that Sir John had a falling out with the Olympic Committee over his role as the musical director for the games.
Johnny Cash (apex)
The Johnny Cash Show - album - was created in 1970-10.
He recorded his songs in a studio and then he put it in the show.
The Johnny Cash Show - 1969 - 2.14 was released on: USA: 6 January 1971
The Johnny Cash Show - 1969 - 1.29 was released on: USA: 22 April 1970
Johnny Cash (apex)
The Johnny Cash Show - 1969 The Johnny Cash Christmas Show 2-13 was released on: USA: 25 December 1970
The Johnny Cash Show - album - was created in 1970-10.
He recorded his songs in a studio and then he put it in the show.
Yeah, he even got his own show : The Johnny Cash show.
The Johnny Cash Show - TV series - was created in 1969.
How should I know? Ask Elton John.
The Johnny Cash Show - 1969 was released on: USA: 7 June 1969
The Johnny Cash Show - 1969 - 2.14 was released on: USA: 6 January 1971
The Johnny Cash Show - 1969 - 1.10 was released on: USA: 16 August 1969
The Johnny Cash Show - 1969 - 1.11 was released on: USA: 23 August 1969
The Johnny Cash Show - 1969 - 1.13 was released on: USA: 6 September 1969