The original production of the musical comedy began in June 1954 and surprised the British theatre community (including the writers) by moving to a then-record-setting run of 5-1/2 years. Its launch was at the Theatre Royal Bristol.
Mr. Slade and actress Dorothy Reynolds (who is credited with Mr. Slade for co-writing the book and lyrics) had been commissioned to write a summer show for the Bristol Old Vic Company, where he was music director. It was reportedly written in six weeks.
"It was scheduled to run just three weeks, but fate and a London management intervened," Mr. Slade wrote in liner notes for a 1976 London revival cast recording.
In August 1954 the Bristol production opened at the Vaudeville Theatre in London and stayed more than five years. At the time, it was the longest-running musical in British theatre history. The show has had many productions around the world, but unlike its similarly light and airy contemporary sister, Sandy Wilson's The Boy Friend, the musical did not capture the imagination of an American audience over the years.
The musical bested the run of The Boy Friend in London and overtook the performance count of the previous longest-run show in England, Chu Chin Chow.
Mr. Slade was one of three sons of a barrister, GP Slade. The composer learned piano at prep school in Oxford. In his last year at Eton he was encouraged to pursue music.
At Trinity College, Cambridge, John Barton commissioned him to write an undergraduate musical, Lady May, for May Week. Titles of his future shows indicate the lightweight nature of the plots: Bang Goes the Meringue, Free As Air, Hooray for Daisy, Follow That Girl, Wildest Dreams, Nutmeg and Ginger, among others.
After university, Mr. Slade attended the drama school of the Bristol Old Vic. He wrote incidental music for the troupe's Two Gentlemen of Verona, which transferred to the Old Vic in 1952. For the Bristol Old Vic, he and two others (including Reynolds and James Cairncross) volunteered to write a Christmas musical. It was called Christmas in King Street, and helped Mr. Slade earn the position of music director at the Bristol Old Vic.
He penned music for the plays The Duenna, The Merry Gentlemen and a musical version of The Comedy of Errors (with lyrics by Reynolds, who was 17 years his senior).
The title for Salad Days was reportedly suggested by the theatre barmaid, who had heard a line from Antony and Cleopatra. The reference is to days of youth. The writers' provincial lark became a smash — and made them rich.
Mr. Slade played piano in the pit of the London production for the first 18 months of the run there.
A West End revival of Salad Days appeared in 1996.
Critics did not embrace Salad Days, but that didn't keep the show down. In London, it ran longer than My Fair Lady. Lionel Bart's Oliver! eventually surpassed it.
Mr. Slade also penned a musical, Trelawny, based on Trelawny of the Wells in 1972. None of his work would match the success of Salad Days, but it did not stop him from writing and exploring projects over a long career.
A lifelong bachelor, Mr. Slade is survived by his sister Pauline, and brothers Adrian and Christopher.