The quintessential English wit was devastated by the first performance of his musical in 1954, when much of the score was cut because the leading lady could not sing it.
Now John McGlinn, an American conductor, has tracked down the score and pieced together missing parts for its first performance in 40 years, to take place during the Covent Garden Festival in London next month.
Graham Payn, Noel Coward's companion and a star of the original production, is hoping to travel from his home in Switzerland for the revival.
Kenneth Richardson, the festival's director, said: "People will love it, because it's Noel Coward and it's got that hallmark of easy melodic invention. But what will interest people is how operatic it is. It has this very lush, operatic score."
After the Ball was written in 1953. It is based on Oscar Wilde's Lady Windermere's Fan.
In his diaries of the time, Noel Coward noted: "The music is pouring out and I can scarcely go to the piano without a melody creeping from my fingers ... it is most extraordinary."
But because of his tax exile in Bermuda, Coward was unable to attend rehearsals in Britain until the musical was well into its pre-London run in the provinces.
When he saw the show in Bristol on 1 April 1954, he was bitterly disappointed. He thought it "restless and untidy". The orchestra was "appalling" and the orchestration "beneath contempt".
"Graham [Payn], thank God, was really very good indeed," he wrote. But he regarded Mary Ellis, an acclaimed opera star of the time, as a disaster in the diva role of Mrs Erlynne. "Mary Ellis acted well, but sang so badly that I could hardly bear it."
The orchestrations were rewritten and the show re-vamped before it opened on Shaftesbury Avenue in London for a run of several months, but it failed to become the hit Coward had hoped for.
John McGlinn, who will conduct the complete version next month, said Coward had a reputation of something of a "washed-out playboy" by the time the show opened.
"I don't think anyone was willing to grant him that he could write this profoundly true, deeply emotional piece," he said.
Yet when Mr McGlinn found the music, "I just sat there, thinking he never wrote anything like it before and never wrote anything like it again".
This year is the centenary of Coward's birth and Mr McGlinn began investigating After the Ball, which he knew only by name, to fill in the gaps in his knowledge.
"I'm now so eager to hear the orchestra play it," he said. "I can't wait. I think people are going to be gobsmacked."
Graham Payn, whose role as Mr Hopper was much enlarged from the original play, said he had fond memories of the cast, despite the problems.
And he was pleased that the music was going to be performed at last. "[Noel] would be delighted, more than pleased," Mr Payn said.
"He liked the score, he thought it had good melodies, as indeed it has. He composed such good music. It was such a pity that all the Mary Ellis stuff had to be cut."
The show at the Peacock Theatre in London on 27 May will be a concert performance with an abridged version of the dialogue.
But the efforts of Mr McGlinn mean that original songs, such as a 300- bar aria involving the character of Mrs Erlynne, will be heard on a London stage for the first time.