It’s been Monty Python week in opera in and around London: following hot on the heels of Terry Gilliam’s amazing Benvenuto Cellini for ENO, Garsington Opera have staged the first ever full UK performance of Jacques Offenbach’s absurdist operetta Vert-Vert, which I can safely assume is the only opera ever to start with a dead parrot.

In fact, the opera is named after the said dead parrot, the much beloved pet of a crowd of convent schoolgirls, two of whom are secretly married to handsome young dragoon officers (their assistant head “Mademoiselle” Paturelle is also secretly married to the dancing master), a third, Mimi, being in love with the simpleton Valentin, to the point where she persuades the other girls that Valentin should be adopted as a replacement for the late lamented bird and take on his name. Meanwhile, plans of escape are afoot... I don’t need to go on. You’ve by now got the idea that this is a very, very silly opera.

Vert-Vert is an operetta which, if done badly, you could imagine being a total train wreck. The way Garsington did it last night, it was two and a half hours of unalloyed pleasure, excelling in every department. There was some great singing, delicious orchestral playing, side-splitting comic acting, wonderfully clever choreography and truly mouth-watering staging and costumes.

The score is the work of a musical magpie, with echoes of just about every major opera composer for the preceding century. The overture is a crescendo that Rossini would have been proud of, performed with such delicate lightness of touch by David Parry and the Garsington Opera Orchestra that it got a huge round of applause before the real proceedings began. The funeral march that follows echoes Chopin, there’s a hefty dose of Mozartian singing, plenty of Italian bel canto, snatches of Bizet; Mademoiselle Paturelle even gets a short passage that sounds straight out of Wagner. I find it hard to tell whether Offenbach was deliberately sending up all these styles to amuse his audience, or whether he wrote the score that way because he could, out of love for all that music and a desire to show off. Either way, the result, certainly as performed by Parry, is a marvellous confection, bursting with melody, always in movement and brimming with joy.

Vert-Vert has thirteen named roles, the majority of which have a notable contribution to make, and all of which were sung well: for want of space, I’ll highlight just five. Robert Murray was outstanding in the title role. His tenor is clear and sweet-toned, and projects well, clearly audible even when accompanied by fortissimi from full orchestra and chorus. And when required, Murray produces phrases of pure nobility, with a voice that would suit a Tamino. Fflur Wyn’s voice is also light and pretty, very much in the soubrette style although Mimi isn’t strictly a soubrette role. She negotiated the elegant tracery of Offenbach’s lines with grace, as well as making us laugh with almost every movement and expression. Yvonne Howard was in fine voice and gloriously redoubtable as the matronly Mademoiselle Paturelle. As the “famous singer” La Corilla, Naomi O’Connell didn’t seem quite as much at home with the comic timing of a vamp role, but she brought the house down with a send-up of coloratura singing, in which she assures the audience that they needn’t worry too much about listening to the words, because it’s coloratura and they won’t be able to understand a syllable. And Geoffrey Dolton gave us the comic highlight of the evening at the beginning of act III, as the dancing master Baladon expounds to the tutu-clad girls the history of dance from the Pavane to the Ländler, accompanied by riotously funny choreography by Ewan Jones.

Throughout the evening, the movement on stage, danced or otherwise, was magnificent, continually inventive and hilarious – for which huge credit goes to Jones and director Martin Duncan. And the picture of general excellence was completed by Francis O’Connor’s designs. The set centred round a photo-realistic model of a French 19th century pile with great attention to detail, complete with faded stonework, tiled roof, little domes, turrets, ornate pilasters and mansard windows. Costumes were a feast for the eyes, scarlet and leather for the dragoons, gorgeously crafted school uniforms for the girls and an exquisitely devised potpourri of mediaeval nonsense for an opera-within-an-opera scene at the end of Act II.

One last special mention: operetta works because of the jokes, and French operetta in English only works if you get the translation right – a difficult task when you have to keep it funny, keep it light, keep it singable and keep some semblance of the original. Tonight’s translation was by the conductor, who, in an interview in the programme, explains the effort that he put into making the words fit onto the music. That effort was richly repaid.

To repeat: Vert-Vert is a very, very silly opera – more a series of comic sketches than an integrated work. But in this production, everything delights, and I both laughed and enjoyed the music throughout. If operetta can be done at this level, I wish there were more of it.