LPO, Jurowski, RFH / LSO, BBC Singers, Rattle, Barbican review - spiderwebs, sublimity and a powerful speech

Complex, ambiguous late romantic works in concert programmes need something more direct to keep them company. Mozart and Richard Strauss make excellent bedfellows (and Strauss was an extraordinary Mozart interpreter): no wonder Vladimir Jurowski’s Saturday night pairing worked well. But Mahler and Poulenc? That wasn’t Simon Rattle’s original intention; but in campaigning for the BBC Singers by inviting them to follow his LSO Mahler 7, he hit upon a rare ideal.

In terms of post-concert coverage, most of the thunder has been stolen by Rattle's speech after the interval. Which, under the circumstances, is as it should be: he's probably the only conductor most Brits have heard of, and he has a vital message to deliver ("but why is he abandoning us?" asked one of my students today. I'd put it differently – he knows he can do much more musically in Munich, and surely he'll carry on fighting in his many return visits).

Rattle's words were well calibrated, but hard hitting when they needed to be. He referenced Arts Council England's devastating cuts and "the proposed vandalism by the BBC, of which the closure of the BBC Singers was only the tip of the iceberg" (don't expect the speech to appear in Radio 3's broadcast of the concert...). He nailed where the UK stands, musically speaking: still at the top, "but the closeness to the edge means that as support is constantly cut, there is no room to manoeuvre, and inevitably organisations will start to fail". He pointed out the obscenity of all that mindless proposed destruction: "we could help, if we were ever asked or consulted". And he lambasted "a political ignorance of what this art-form entails...there seems a stubborn pride in that ignorance". So we must be fierce and stubborn too.

What I heard around this speech, earlier in the day – English National Opera's total brilliance in an afternoon performance of Blue, the emotionally hard-hitting opera about police shootings of young black people in the USA – as well as on the previous evening, with another orchestra at the top of its form and the previous Saturday, a non-stop musical feast of an evening at the Southbank Centre from the National Youth Orchestra of Great Britain would fire up any politicians worth their salt. But which of them was at any of these events? (The only answer I have is that I saw the admirable Chris Smith on Sunday night.)Mahler's Seventh Symphony – also, astonishingly played by the National Youth Orchestra of Scotland under inspirational conductor Catherine Larsen-Maguire just over a week earlier – is the toughest challenge of the ten in its exposure of instrumental challenges. It's long been a Rattle speciality (performance pictured above). The live Aldeburgh Festival recording of it he made with the City of Birmingham Symphony Orchestra in 1991 – which he insisted EMI use instead of a studio recording with which he'd been less happy – was my top choice for BBC Radio 3's Building a Library that same decade (there have been many incandescent Sevenths since then, so the situation may well have changed). His Berlin Philharmonic Orchestra Prom seemed as far as it was possible to go in supernatural sounds until Kirill Petrenko conducted it with the same orchestra there two years ago. And it was always going to be fascinating to hear what he drew from a London Symphony Orchestra on peak form.

Predictably, the parade of phantasmagorical sounds as Mahler focuses on night noises, a serenade near daybreak and a civic ceremonial in broad sunshine astonished as ever, and not always in the usual places. Rattle's overall grip brought more trenchant detail than ever in the late stages of the first-movement carnival float, belonging to a tragedy Queen of Night, and of the finale, a pell-mell street party which only needs the keenest of articulation to hold the interest. The micromanagement may have sacrificed something of the ghosts' high-noon waltz at the centre of the symphony, but further refinements at the quiet end brought special magic to the two "Night Musics".

The LSO musicians knew it would be a special event: I guess that's why oboist Olivier Stankiewicz was there taking a smaller role than his co-principal, Juliana Koch. She played with aching intensity, while the more obviously exposed solos – from the tenor tuba (uncredited), first horn Timothy Jones (special whoop in the opening fanfare of the second movement) and first trumpet James Fountain were as perfect as I've ever heard them (★★★★★). If anything, the individual characterisations were stronger here, especially in evocations of the animal world, than from the London Philharmonic principals the previous evening in Strauss's "opera for orchestra" and most kaleidoscopically realised symphonic poem Don Quixote. Perhaps that was how Jurowski wanted it, less pictorial than usual so as to focus on purely musical values. But the beauty of Strauss's work here is that you can have it all ways: descriptive homages to the more outlandish pranks of Cervantes's Knight of the Woeful Countenance and his garrulous squire Sancho Panza, brilliant variation form and soulful concerto stretches, very poetically taken not by the usual visiting star but by wonderful LPO principal cellist Kristina Blaumane (pictured above in another performance). Perhaps if Jurowski revisits the score, as he so often does, there will be time for her and viola player Richard Waters to relax in to the fun of their characterisations. But one aspect, at least, was peerless, the textural clarity in Strauss's spiderweb of sound. With woodwind led by flautist Juliette Bausor flying through the air in the journey on the wooden horse, who needs a wind machine (aptly discreet here) for giddying effect?

The surprise success of the evening was Jurowski's typically thoughtful way with Mozart's miraculous Symphony No. 40, the first time he's ever conducted the work. Opting for authentic proportions, starting with eight first violins, he achieved a transparency at fleet speeds which reminded us how the wind-ensemble writing here is as exquisite as in the late piano concertos. What subtlety: you heard not only the doleful first-bassoon counterpoint in the first-movement recap, but the two instruments limning other crucial passages. All repeats were welcome, along with a reminder that Mozart didn't really write slow movements in the late symphonies: at a proper Andante pace, we had a bittersweet minuet to follow the Molto allegro drama, and more darkness of purpose in its sequel (★★★★). Sunday's revelation came second in the order, due to the BBC Singers' late arrival on the scene. Poulenc's Figure Humaine is his resistance masterpiece, one of his greatest works equal to any pillar of the a cappella choral repertoire. Setting privately-despatched poems by his friend, the great French poet Paul Éluard, its eight movements were smuggled out to London while Paris was under Nazi occupation, and premiered by who else but the BBC Singers (or Chorus, as it was then known), albeit in an English translation.

Éluard's painful shards evoking the monster enemy and its oppression take a heart-leaping turn in the seventh number, "Un feu sans tache" ("A flawless fire"), as a fire-spitting fugue gives way to mystical intensity routing "stupidity, dementia and vulgarity" with 'humanity and brotherhood'. This is the real catharsis, magnificently moulded under Rattle, while "Liberte" comes as a fleet epitaph, ending in a blaze (ffff) on that long-delayed word with a blistering top E in alt from two sopranos, .What a way to end an embattled but ultimately exultant weekend of music-making.  

• LSO/BBC Singers concert recorded for future broadcast on BBC Radio 3
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