Deutsches Symphonie-Orchester Berlin, Metzmacher, Royal Albert Hall

Swimming in the soup of the lesser late Romantics can be hard work. You get to admire the pretty variegated fish as you flounder, waiting to be buoyed up by a bigger idea. Then one comes along and nudges away so insistently that you nearly drown. Both extremes had to be borne in the first half of last night's Prom, with Ingo Metzmacher steering a supple course between the lazy devil of a Schreker operatic interlude and the placid blue sea of Korngold's Violin Concerto. The one interesting question that kept me afloat in viscous waters was: could he turn master oarsman and steer the superior, packed-to-bursting vessel of Mahler's Seventh Symphony?

Only up to a point. He launched Mahler's opening trudge - which it's hard to believe was inspired by the movement of oars on an Alpine lake - well enough, despite a less than phosphorescent tenor-horn solo, and wound it up to the first movement's march mania with aplomb. But I wasn't feeling Mahler's pain, and it was a bit of a giveaway that Metzmacher made the oddest clownish gestures in the lyrical counter-theme, a bit like a camp hairdresser readjusting the Marschallin's coiffure. Sometimes he needed the batonless flicks to bring out a scary detail, but he allowed too much in this varied symphonic suite to coast.

You really need to keep the placid Schubertian trios of the second movement's night watch on their toes; Metzmacher let them meander. The scherzo's haunted ballroom fizzled out at the two-thirds mark, and the  whole of the second "Night-music" passed in a pretty haze. What a shame: it can be the most singular of all Mahler's symphonic movements, but the guitar and mandolin serenaders need to be more equal with the front desk strings than they were here, the shadows in the garden longer and more trenchant. At least Metzmacher had made an interesting connection: in the absence of a real slow movement, the "Night-piece" from Franz Schreker's opera Der ferne klang which opened the evening provided an alternative. Not exactly a masterly one; despite the haunting perspectives managed by the Berlin players, not a single theme held fast in the imagination. Still, if anywhere is suited to this plush reverie, it has to be the Albert Hall.

But we're still talking Mahler's superior inventiveness here, and I can never agree with those who find the daylight ceremonials of the Seventh's finale a let-down after the night parade. It's Meistersinger on speed, with dainty interludes providing a bit of a rest on the civic green (again, those were a bit too slack to keep the momentum here).  Earlier, I'd found the DSO first trumpeter overbearing: it might have been where I was sitting, but I felt demonised by the way he stuck out from the soft-edged crowd in the first movement. No such problems in the finale, where the trumpet trio blended and brilliantly mastered its insane high-wire revels.

If only Metzmacher had been able to summon a more visceral sense of off-kilter jubilation. It was a decent, never wayward interpretation, one which would have given newcomers a good taste of Mahler's most bizarre symphony, but no match for the eternal vigilance of Runnicles or the best bits of Gergiev in last week's Mahler Proms. And it's a shame this Berlin orchestra's strings and woodwind lack real personality and definition - not easy, I know, to achieve in the Albert Hall.

Mind you, I  admit I was in a bit of a torpor after having to sit through the Korngold Violin Concerto for the second time this year, and dreading that utterly superfluous second movement when the first has said it all - and again, and again - in terms of romantic lyricism. Only the brilliant and easy Leonidas Kavakos could make me look forward to at least parts of it, and along with Metzmacher he even managed to make beguiling work of the central Romance's dying fall. But oddly the hell-for-leather dash through the Hollywood romp of the finale - give me Kleinsinger's Tubby the Tuba any day - had less charm than Andrew Haveron's performance with the BBC Symphony Orchestra back in February.

Could Kavakos redeem the sense of a second-rank composer on auto-pilot with one of his usual, magical encores? Well, unlike at Verbier, where he'd chosen pure poetry in Ysaÿe to follow his unsurpassable interpretation of Bartók's Second Violin Concerto, he settled for more high jinks: a fiendish violin impersonation of a guitar in Ruggiero Ricci's transcription of Tarrega's Recuerdos de la Alhambra. Its insane technical demands, disproportionate given a ditty so slight, had even the usually perfect-pitching Kavakos going just a little off the rails, but ever so charmingly. And we did need some genuinely light relief in the romantic twilight. No doubt the kids at this very oddly selected "Family Prom" would have enjoyed that, even if the one behind me curled up on his delightful mother's lap and dozed during most of the Mahler, stirring for the giant cowbell-rattling at the end.

• Read theartsdesk's recommendations for the 2010 BBC Proms
• Full listings for the 2010 BBC Proms
• Listen to this concert on the BBC iPlayer for the next six days