FAG in one hand and wine glass in the other – though not one containing Bolly – Joanna Lumley stood out from the first-night crowd on the forecourt of Frank Matcham’s lovely opera house in Buxton last Friday.

The start of the Derbyshire spa town’s annual festival – its 38th – came at the end of a high-profile week for the platinum blonde star.

Omnipresent on radio and television, newspapers and magazines, she could not be said to have failed in her promotional duties for a film in which she had been judged Absolutely Fabulous, even though much else about it had not.

As befits a gal from an army background – I first clapped eyes on her in the flesh four decades ago at the Cavalry and Guards Club – Ms Lumley “does” duties rather well – and not only where Gurkhas and garden bridges are concerned.

Opera is another area where duty calls, out of a proper loyalty to her husband of 30 years, Stephen Barlow, who, among much other activity in the musical world, is artistic director of the Buxton Festival.

He is conducting the superb production of Beethoven’s Leonore that graces this year’s programme.

But in common with Oscar Wilde’s Gwendolen Fairfax in the matter of speaking one’s mind, duty for Joanna is evidently also a pleasure where opera is concerned.

Could she – could anyone – not be entertained, impressed and deeply moved by a production of the quality of this Leonore, an earlier and longer version of the better-known Fidelio? As it happens, this opera is, in part, a celebration of marital duty in which the title character – superbly sung here by Kirstin Sharpin – disguises herself as a man to trick her way into the state prison as a warder in order to free her husband Florestan (David Danholt), who is languishing in its depths.

A happy consequence of the work’s greater length (I heard it wittily called “the director’s cut”) is the better examination of Leonore’s relationship with the head jailer’s daughter Marzelline (Kristy Swift) who has ambitions to wed the new “man”. There is more, too, from Jacquino (Stuart Laing), the swain she plans to throw over.

Unfortunately, an element of absurdity is introduced when Leonore and Florestan finally meet and, during a lengthy stretch of the action, seem not to be altogether sure of each other’s identity. Irreverent as it may seem, I found myself thinking of Louis Jordan’s 1944 song, Is You Is Or Is You Ain’t My Baby?.

Buxton’s second opera offering, which I enjoyed on Saturday night, is Bellini’s I Capuleti e i Montecchi, another work that tells a story better known in a different form, that of Romeo and Juliet.

The pared-down version, unlike Shakespeare’s, does indeed supply a “two-hour traffic of the stage”, with demanding work for the chorus. Star of the night for me was the Canadian mezzo-soprano Stephanie Marshall as Romeo. Here is a singer in a breeches role that really looks and acts the part, especially in the tender scenes with Giulietta (Sarah-Jane Brandon). Justin Doyle conducts brilliantly.

Buxton Festival continues until July 24, with a third major opera in Handel’s Tamerlano. For details, visit buxtonfestival.co.uk My trip to Derbyshire was preceded by a farewell visit to Northington Grange, near Winchester, for the last staged production there by Grange Park Opera.

Verdi’s hugely demanding work Don Carlo is superbly done under conductor Gianluca Marciano, bringing a fitting climax to GPO’s 19-year history here.

The company’s founder and boss Wasfi Kani is right to think it the best thing they have done.

Clive Bayley sings superbly as King Philip of Spain who stirs up dynastic and religious upset when he marries the French princess Elizabeth (Virginia Tola), who had been promised to his son Carlos (Stefano Secco).

In 1998, when GPO began, it would hardly have been imagined that such a mighty work as this could be attempted. Country house opera, so called, has indeed come a long way.

One of its greatest champions has been the indomitable Wasfi, as brilliant in fund-raising as over matters artistic. She was with Garsington Opera before leaving to set up at the Grange. Now the whole operation is to move from next year to West Horsley Place in Surrey, where Joseph Calleja will supply a starry start as Cavaradossi in Puccini’s Tosca.

He will sing in a new four-tiered theatre seating 650. Its £10m cost is already half met through an appeal spearheaded by Bryn Terfel and Joanna Lumley.

Thus we end where we began.