Prom 46: West-Eastern Divan Orchestra, Barenboim

By the time we got to the end of this Prom, with four of the five encores – the whole of Bizet’s Carmen Suite – cannily crafted to bolster the short official programme, most of the rightly euphoric audience had forgotten the most unsatisfying first half so far this season. Perhaps I start from an ungenerous standpoint.

Of course Barenboim’s orchestra of players from Israel and the Arab world is a beacon of light, communication and collaboration in the worst of times, and when I first heard it in 2004 the intensity was unrivalled; last night he seemed to be deliberately dampening it down at times.

It’s always a wonderful thing to see youth at the Proms, which means a younger audience in parts of the hall, too. But the music-making has to stand by itself, and once we’d applauded the enterprise, only treasurable stretches of this evening matched up to the perfect communication of the European Union Youth Orchestra’s Prom – unsurpassable in any case – and the National Youth Orchestra spectacular last week.

Despite the warm expectancy of the packed house – the Arena the fullest I’ve seen it this season – things got off to an uncertain start. Mozart’s Marriage of Figaro Overture is the wrong masterpiece for the Albert Hall, which can take susurration, but not at speed (though the third theme, deliciously pointed, projected individuality well enough). Its relatively small ensemble meant a major platform reshuffle after less than five minutes. The remaining 24 of the first half were devoted to two new works making a significant statement side by side in that one composer, Ayal Adler, was born in Jerusalem, the other, Kareem Roustom (pictured taking his bow), in Damascus.

Good for history, then, but not for music itself, at least in Adler’s case. When does an orchestra decide to bin what it’s commissioned? Presumably you're familiar with the composer when you ask him or her to write a piece. On this evidence, Adler has none of the individuality effusively claimed in his programme biography. Within seconds of Resonating Sounds, you know by the indiscriminate use of six percussionists that this is going to be a new piece like a thousand others: shapeless, rhythmically inert, without thematic hooks, engaging a large orchestra with big swooshes of sound just because it’s there: all textures - cueing the ubiquitous word ‘soundworld’, but not an interesting one at that - and no foreground.

Roustom’s Ramal, based both title-wise and musically on a pre-Islamic Arabic poetic metre, at least grabs you at the start, a John Adams takeoff that doesn’t subsequently give you that composer’s sense of moving through space. It’s an audience-pleasing collage of film-music – one of Roustom’s many disciplines, another being string arrangements for Beyoncé and Shakira – and familiar echoes of good role-models: minutes after a moment of stasis with beautifully-scored wind chords promising a main event that doesn’t quite happen, there’s a not inappropriate chant of Brittenesque angst. But even in 12 minutes, I wasn’t sure where the piece was going.

Outstanding solo star of the evening among many, achingly characterful, turned out to be the first bassoon

Trust Ravel to show the real novelty of less-is-more orchestration. Barenboim chose a Spanish symphony in seven movements, perhaps a homage to the orchestra’s annual summer gathering in Seville. The subtle moments were the best: this conductor has always said that in this space you bring an audience in to catch the near-inaudible, rather than straining to reach out, and though the Spanish night at the opening of the Rapsodie espagnole had things that went bump in it from a restless audience, the flurries of clarinets and bassoons were haunting indeed; the outstanding solo star of the evening among many, achingly characterful in the central song of the Alborada del gracioso, turned out to be the first bassoon, though I can’t give her name since none of the players was listed in the programme (security measure?).

Just as fine, if less in the spotlight, was the first horn, kicking off the real highlight of the evening for me, the Pavane pour une infante défunte phrased with infinite sensitivity. A lament for dead children was the one point in the evening where some of us cast sideways to the ongoing conflict and shed a few tears..

Collectively, though, this wonderful team wasn’t allowed to ignite the flames of Iberiana. Barenboim (pictured left sitting it out for the fourth of the Carmen encores) seemed to be beating frantically in the Rapsodie’s final welter, untidily concluded, and that wonderful moment in Boléro where the violins enter with the song for the first time lacked exultation. How much more elan there was in the young musicians' get together - EUYO members plus British youth orchestra players - in the hall the other week. And memories of last year's Prom gambit in twinning Juanjo Mena's BBC Philharmonic with a top-notch flamenco troupe, a surprise success, weren't so easily eclipsed. Boléro can take the militarily fast as well as the sensuously slow approach, but beyond the early stages where rhythm was as deftly coloured as melody, this one didn't quite blaze. Maybe Barenboim was trying to be super-subtle, because when the strings were required to fire up or swoon in the first two of the Carmen entr’acte encores, they did.

Not enough, then, of the full-throttle intensity we’d had from, say, the Borusan Istanbul Philharmonic earlier in the season (and they couched their first-half dud in finer company). But the encores were beautifully done and the Carmen Prelude, presented last of the Bizet four, allowed Barenboim to set aside his baton for the second time after Boléro’s opening string of solos. A little Argentinian tango, postcard from the orchestra’s recent tour there and deftly arranged for brass, wind and percussion, tasted sweet but seemed totemic of the concert as a whole: a passion-low zone.

• Listen to this concert for the next month on the BBC Radio 3 iPlayer
• Highlights to be shown on BBC Radio Four on 29 August