‘Ring out your bells for me, ivory keys! Weave out your spell for me, orchestra please!’ It’s lush stuff, the music of Ivor Novello, and when the Buxton International Festival announced a new musical ‘built around’ his songs, the heart took flight. Novello is one of those fringe passions that are, one suspects, a lot less marginal than fashion might suggest. If his great hit operettas of the 1930s and 1940s – The Dancing Years, King’s Rhapsody and the rest – really are unrevivable (and the jury is still out on that), a sympathetic, newly constructed showcase for his finest material in the manner of the Gershwin reboot Crazy For You might be the next best thing.

The Land of Might-Have-Been is not that show. I’m still not sure exactly what it is, and possibly its creators, composer Iain Farrington, writer (and Festival CEO) Michael Williams and director Kimberley Sykes, haven’t quite worked it out either. The plot is based on the life of Vera Brittain, who grew up in Buxton (she hated the place), and arms were apparently twisted by the late Baroness Williams of Crosby, Brittain’s daughter and a former grandee of the Festival. Superficially, it’s Testament of Youth: The Musical, although a disclaimer in the programme insists otherwise. The Vera on stage is such a prig that she sends you back to the book in disbelief. Surely the real Brittain couldn’t have been as insufferable as this?

Actually, she is, at times; but she’s also conflicted, perceptive and painfully honest, none of which makes it on stage. The Land of Might-Have-Been begins in 1914 but the central characters possess a full set of 21st-century values and social attitudes and are duly appalled by the braying toffs and baying plebs of the period they inhabit. ‘Read all about it! Germany declares war!’ yells a newspaper-boy and you can fill in the rest. Futility of war. Soldier-poets dying as cattle. In all probability, only the fact that Novello’s best-known song refers to lilacs spared us a final shower of poppies.

Still, the list of musical numbers is promising and we do get (among others) ‘Waltz of My Heart’, ‘I Can Give You the Starlight’, ‘Glamorous Night’ and ‘We’ll Gather Lilacs’, in one form or another. Farrington has re-orchestrated them, Michael Williams has rewritten the lyrics, and when it all works, it works beautifully: ‘My Dearest Dear’ becomes a moment of hesitant intimacy between the lovers Edward (George Arvidson, camping it up just enough) and Bobbie (Kit Esuruoso). Their relationship is easily the most persuasive element of the show, and along with Alexander Knox (as Vera’s doomed fiancé) the male leads really can sing, with light, shapely voices that Novello might have rather enjoyed. The same can’t honestly be said of Audrey Brisson as Vera. She’s energetic, but her voice is wholly unsuited to this idiom, and heavy-handed amplification doesn’t do it any favours – any more than the shonky sets and scrappy choral singing help the piece as a whole.

Meanwhile the ratio of vintage Novello to soupy underscoring dwindles throughout, and the liveliest production number (the song they reprise for the curtain call) is a pastiche by Farrington and White. The titles of Novello’s shows should say it all: Crest of the Wave; Careless Rapture; Perchance to Dream. We’re dealing with high romance; delirious escapism, from an era with a lot to escape from. If you’re embarrassed by that – if you see these songs only as lavender-scented relics – you should probably leave Ivor out of it and write a complete original score of your own. Whatever Shirley Williams might have said.

Buxton’s in-house productions are usually better than this and sure enough, the Festival’s new staging of Mozart’s Il re pastore is in another class. The shepherd lad Aminta (Katie Coventry) turns out to be the deposed king of Sidon. Will his new-found royal status mean heartbreak for his rustic sweetheart Elisa (Ellie Neate)? Spoiler alert: no. Director Jack Furness leans into both the artifice and the charm, with video footage of the Derbyshire countryside (complete with ambling sheep) serving as backdrop to a cast dressed like figures from a Fragonard pastoral. They treat every tearful sigh, courtly bow and anguished gasp as if the emotion is absolutely real.

The result is as refreshing as it is touching, with the characters’ sorrows and joys silhouetted crisply (but not harshly) against the gentle absurdity of the whole set-up. Amid a loveable cast, Coventry and Neate stood out for the tenderness and clarity of their singing, while the 19-year-old Mozart’s score (conducted by Adrian Kelly) combines spring-water sparkle with moments – a languishing oboe; a quiet, falling harmony – that go straight to the heart. Furness – whose final, delightful gesture was a masterclass in creating enchantment from utter simplicity – is a director whose star continues to rise.