To the American audience, he is best known for his role as J Pierrepont Finch in the Broadway musical "How to Succeed in Business Without Really Efforting" from 1961, which also became a 1967 film.
For all fans of the TV drama "Mad men", he is also recognized as the advertising agency Sterling Cooper's eccentric co-founder Bertram Cooper, who Morse played during the series' seven seasons and which resulted in five Emmy nominations.
He also got the chance to dust off his old Broadway skills in the series.
After his character Bertram died in "Mad Men", while the TV shows how Neil Armstrong walks on the moon, Morse made a singing and dancing routine to the tunes of "The best things in life are free".
In a 2014 interview with Rolling Stone magazine, Morse said that creator Matthew Weiner had always intended to sing in the series.
Morse himself, however, had to be persuaded, but in the end he thought the scene fit perfectly.
- It was not just 'Go and sing a song and au revoir, Bobby'.
It was Bert who said to Don (Jon Hamm's character): What are you doing?
All this shit you're doing, stop it.
The best things in life are free.
We have just landed on the moon.
Calm down.
Enjoy things while you have them.
Robert Morse turned 90 years old.