Pierrot lunaire, Almeida Theatre, London</br>Fidelio, Glyndebourne Opera, Sussex<br/>The Merry Widow, Holland Park Opera, London

H istorical reconstructions have traditionally been associated with the doges and dulcians of the Renaissance. Could this be about to change? Earlier this year, BBC2's Riot at the Rite recreated the notorious 1913 Paris premiere of Stravinsky's ballet. This week, the 1912 Berlin premiere of Schoenberg's Pierrot lunaire was recreated live by director Mike Ashman, mezzo-soprano Sally Burgess, and the Almeida Ensemble.

Clearly, German theatre-goers were more open-minded than French balletomanes, for when Albertine Zehme first performed Pierrot lunaire, she went on to tour 11 cities. At the Almeida, just one performance was scheduled, though a more arresting impersonation than Burgess's is difficult to imagine. With Tim Payne (clarinet), Andrew Ball (piano), Miranda Fulleylove (violin/viola), Sophie Harris (cello), and Nancy Ruffer (flute) playing behind a screen, according to Schoenberg's original directions, Burgess conjured the necrotic fantasies of Albert Giraud's moonstruck clown with a disc of light and a single chair as her only props. Waxen of face, sometimes childlike, sometimes grotesque, and clothed in black, she howled, whispered, barked, crooned, gasped, spat, trilled and keened at the moon; variously greasy, ghostly, voluptuous and electrifying of tone.

It says a great deal for Burgess's musicianship, that of the Almeida Ensemble, and that of conductor Richard Bernas, that at no point did the screen interfere with the fluidity of the performance. If anything, the musicians' invisibility sharpened one's ears to the extraordinary versatility of Schoenberg's instrumentation, to the pallid flute of "Der kranke Mond", the coagulated drag of cello and piano in "Nacht", the searing clarinet of "Die Kreuze", and the sickly sweetness of the strings' "alter Duft". Musically and theatrically, this was an event of astonishing force.

When Deborah Warner's wire cage and washing line production of Fidelio opened in the balmy months before Al Qaeda attacked America, it was something of a sensation: the first British staging of Beethoven's opera to be played on period instruments, and the first to reference the death of Yugoslavia. Five years later, the London Philharmonic Orchestra have replaced the Orchestra of the Age of Enlightenment, and wire cages are now inextricably linked with Guantanamo Bay. If Jean Kalman's sets have dated, and the orchestral textures have dulled, Warner's direction remains strong. As might be expected, Peter Coleman Wright's smooth, insinuating Pizzaro and Anja Kampe's passionate, girlish Leonore dominate the cast. Most touching, however, is Warner's attention to the little people in this heroic drama: the reunited husbands, wives, brothers and sisters of the chorus, the faint-hearted gaoler Rocco (Brindley Sherratt), and the heartbroken ingénues Marzelline (Lisa Milne) and Jaquino (Andrew Kennedy).

Though Mark Elder largely fails in what seems to be an attempt to recreate the prismatic, layered sound of period instruments with their homogenised late-C19th counterparts, the vibrato-free opening of "Mir ist so wunderbar" - a quartet so beautiful that it seems to stop time - is breathtaking. It is also quite exquisitely sung by Milne, Kampe, Kennedy and Sherratt, which makes this the second Glyndebourne production in one season to have raised the bar on ensemble singing to a dizzying height. Concert performances aside, I doubt I will hear a better sung Fidelio.

Bathing beauties, young blades in tennis whites, high-kicking grisettes, tap-dancing waiters, 'Allo 'Allo accents, and Erté evening gowns collide in Tom Hawkes's bright, breezy Art Deco production of The Merry Widow for Opera Holland Park. As the eponymous heiress, Rebecca Caine slips effortlessly between artful flirtation and artless candour, looking a million dollars and singing with a sweet, delicate soprano. Ian Caddy's entertainingly twitchy Ambassador has more than a touch of Leonard Rossiter, while Charlotte Page's pretty, pouty Valencienne is delightful. With charlestons, waltzes and can-cans galore - choreographed by Jenny Weston - this production is a positive prairie oyster to those who suffered the long, dark night of the soul that was Welsh National Opera's abysmal Merry Widow.

a.picard@independent.co.uk

Fidelio (01273 813813) to 3 August; The Merry Widow (0845 841 1111) to 14 July