I never verified it, but I once read that Johnny made more than half his money on the royalties and residuals from Suicide Is Painless. (MASH theme song)
With everything else he did, he signed a spectacular deal on that tune, and likely still gets $ when the show plays in syndication.
If accurate, pretty shrewd business move by Johnny!

Robert Altman specifically challenged him to write the tune for "the dumbest song ever written" to be used during the funeral scene. Altman would then write the lyrics. When he couldn't come up with lyrics that, in his estimation, were sufficiently stupid, Altman asked his 14-year-old son to do it. Mike Altman wrote the lyrics in five minutes.

Altman has said that his son made far more money on his share of the royalties for that one song than he did making the movie.

It's a testament to how great the music is for that "stupid" song that it's stood the test of time all these years.

I had never heard that!
Thanks, Dave.

sing along to the theme music. He explained that the TV network was against the supposed praise of suicide.

I think I'll go watch some mash now.