Berlin Philharmonic / Rattle, Barbican / Southbank, London<br/>Troy Boy, Upstairs at the Gatehouse, London

Suspended on the heartbeat of a single harp, Mahler's Fourth Symphony stretched to infinity in Sir Simon Rattle's performance with the Berlin Philharmonic at the Barbican last Tuesday.

Its eyes cast up to the heavens, feet rooted in the dense forests of German folklore, this scorching, glittering, hallucinatory work shed its belittling reputation as a transition piece. "Kein Musik ist ja nicht auf Erden ..." sang Christine Schäfer. This could be the orchestra's motto: "No music on earth can compare with ours." At that moment, and in Sunday's performance of Schoenberg's Chamber Symphony at the Queen Elizabeth Hall, and in the savage, ecstatic drama of Mahler's Third Symphony at the Royal Festival Hall on Wednesday, she was right.

Cynics will have squirmed at the hyperbole that preceded Berlin's London concerts. Few music-lovers take seriously the accolade of World's Best Orchestra, which surely depends on the three-way chemistry between a body of players, their conductor and the repertoire. For those of us who heard Mariss Jansons's Resurrection Symphony with the Royal Concertgebouw Orchestra last year, even the title of World's Best Mahler Orchestra would be difficult to call. But if the aim of this four-day, three-venue residency was to remind us of what the Berliner Philharmoniker sounds like at its most impassioned and intellectually engaged, it succeeded.

Rattle has often been accused of micro-management. Here, that attention to detail paid extraordinary dividends, both in the performances – the violent sensuality of his rubato, the extremity of his tempi, the barely-there pianissimi, the misericord grotesquerie of his scherzi – and in the programming. In the second of Mahler's anniversary years, here was a new perspective and a fresh context: from the blurred beauty and barely-disguised frustration of the 16-year-old composer's Quartet movement in A minor (pianist Bishara Harouni coped well with what is essentially a reduction of an uncomposed orchestral score), to Schoenberg's very different responses to the same Teutonic tradition – the String Quartet No 2 and Chamber Symphony. Schubert and Haydn gave the Viennese backstory, while Stravinsky's Apollon musagète was either there as a foil to the neo-classical strain in Mahler's Fourth Symphony, or simply to display the athleticism and precision of the Berlin strings in a work that requires only half their number.

More seductive was the folkloreish, pantheistic thread that extended through the series from soprano Anna Prohaska's Litanei and Entrückung (the third and fourth movements of the Schoenberg quartet) to Schäfer's hymn in the Fourth Symphony, St Ursula laughing merrily as Saint Martha fries the fish caught by Saint Peter. This was the song of a woodsprite, not a child: a seductive fantasy of life without rules or inhibition. You could smell the sap of pine trees in Brahms's ravishing Es tönt ein voller Harfenklang (exquisitely realised by principal horn-player Stefan Dohr and harpist Marie-Pierre Langlamet), while Nathalie Stutzman's grave lament in Zarathustra's Mitternachts- lied (with keening portamento woodwind) and the raucous "Bim! Bim!" of the Eltham College boys suggested a society infinitely more diverse than that in the human sphere.

I'm not alone in harbouring violent feelings towards the man who shattered the final silence with a goaty shout of "Bravi!" – very possibly the same culprit who, in November, broke the spell of Jonas Kaufmann's Schöne Müllerin. But luxury indeed, to hear what must have been, at that moment, the World's Greatest Orchestra and not think of their virtuosity, but think instead about the ideas behind the music they had played.

While Blackheath Community Opera battles Greenwich Council for funding, the notion of going for a quiet pint has all but disappeared in north London. With the runaway success of OperaUpClose's La Bohème, and the opening of London's Little Opera House at the King's Head, pub opera is booming in the capital, driven by the work-hungry alumni of the city's four conservatoires. Vocal coaches may suck their teeth at singers taking roles that are too big, too soon, but every now and then, the right performer finds the right part, at the right time. And so it was with gamine Rosalind Coad in Kit Hesketh Harvey's adaptation of Offenbach's La belle Hélène in Highgate's Gatehouse.

Retitled Troy Boy and cut to a manageable size for the Merry Opera Company's young cast of 12, Hesketh-Harvey's translation is familiar from English National Opera's unsexy revival of Laurent Pelly's sexy Châtelet production. Here the setting is a Greek taverna in Chislehurst, where Coad's Helen drowns her sorrows in a bottle of Metaxa before locking eyes with a handsome waiter, Christopher Diffey's Paris.

With stylish accompaniment from a quintet of musicians in chef's uniforms, the company's nubile ancient and modern Greeks scamper about, relishing every hoary pun, while Coad finds the perfect balance of pathos and bathos in Offenbach's sexually-frustrated heroine, her small but sweet voice sparkling in every roulade. Hesketh-Harvey's choreography is haphazard – not that the elderly gentleman who ended up with a nymph on his lap was complaining – but it's hard not to get swept up in the fun.

'Troy Boy': (020-8340 3488) to 5 Mar, then touring)

Next Week:

Chocks away as Anna Picard heads to Glasgow for Harry Fehr's wartime production of Handel's Orlando

Classical Choice

Mark Elder conducts Martin Helmchen and the Hallé in Mozart's Piano Concerto No 17, Verdi's Overture to Luisa Miller and Elgar's Symphony No 1, at Manchester's Bridgewater Hall tonight. English Touring Opera delivers a double dose of Puccini with Gianni Schicchi and Il tabarro at London's Hackney Empire (Fri).