The result is a backstage comedy set in Daventry's freshly formed acting academy where the theatrical jokes fly and a quartet of "old pros" - Doreen Hermitage, Eileen Page, Myra Sands and Elizabeth Seal - are recruited and murderously lament over a life spent teaching stage craft to impossible pupils rather than treading the boards themselves.
Dann is excellent from the off, belting over the eight-strong ensemble in the opening pastiche and wringing every last laugh from her first solo number "It's Bound to be Right on the Night".
Both Blackman and love interest Peter Lynton, played by Josh Little, are suitably dreamy as the young lovers with Little also able to unleash a Kenneth Williams-style comedy in addition to his tender turns. Blackman's strong vibrato is well suited to the role and her opening aria is a treat.
Ivor Novello's final musical, Gay's the Word premiered in Manchester in 1950 before transferring to the Savoy, and harks back further still to a lost theatrical world of operetta and music hall. But there is a timeless humour to many of Novello's numbers, lyrics by Alan Melville, which Dann particularly captures to great effect.
Frank Barrie's later exchanges with the drama school headmistress showcase the piece's more dramatic and touching undercurrents whilst Paul Slack and Jonny Purchase as sub-plot smugglers give Dann ample supply of comic ammunition.
Somewhat squeezed by Alex Marker's impressive floor-to-ceiling set for the Finborough's other current show, Outward Bound, the company almost need to play to the round, but instead appear slightly limited and choreographically restricted by the carpeted stage.
The musical begins to show its age in the act one finale, Daventry's rousing chorus of "Vitality" really isn't much of a show-stopper by today's standards, and has almost outstayed its welcome by the second act reprise.
Whilst perhaps not as perfectly formed as some other lost musical treasures recently seen at the Finborough, Gay's the Word is still an fine miniature musical in which the well-supported Dann excels.