Prom 44: West-Eastern Divan Orchestra/Barenboim, Royal Albert Hall, London/Radio 3

Ovations for the West-Eastern Divan Orchestra started as soon as the first player arrived on the platform. Here was an orchestra co-founded by the Palestinian polymath Edward Said and the Argentine-Jewish conductor Daniel Barenboim, made up half-and-half of Israelis and Arabs, performing for the first time in a country that most Middle Easterners despise. The night before, they had played in the Moroccan capital Rabat, their debut in an Arab state. New York and Tel Aviv may take a while longer, but as tours go, this has to count as brave.

You can't tell how many members come from which state because the policy is not to publish their names - understandable, as it must take courage even to face their neighbours when they say what they are doing. Aged 13-26, they rehearsed with tutors from Barenboim's Berlin Staatskapelle for two weeks in Andalusia, now the orchestra's annual base. This intensive study puts them in a similar bracket of musical experience to the pan-European youth orchestras.

They have a similarly high quality, too: outstanding woodwind, strong brass, strings a degree or two less perfect - you'd compare the violins to a British orchestra rather than a Berlin one, but pretty impressive by any standards. As with all youth orchestras under an inspirational conductor, the performances felt as though everybody was giving 150 per cent. Combined with an already charged atmosphere and a packed house on a humid night, the effect was not only to defeat the Albert Hall's vaunted air-conditioning, but to take the audience to uncommon heights and depths of emotion.

In the Unfinished Symphony of Schubert, the approach was alert, generously phrased and finely timed, the two movements well contrasted in pulse as well as character. Next came the Mozart concerto for three pianos - two and a half, really, since there's one easy part, which Barenboim took while he conducted, and two front-line parts, played here by Saleem Abboud- Ashkar and Shai Wosner. It's a work whose usefulness on symbolic occasions gets it many more performances than its unassuming nature would otherwise command. The outstanding feature this time was to place musical unanimity before soloists' egos: three diverse pianists were making common cause instead of competing.

Beethoven's Eroica Symphony was bound to be a different experience because Barenboim has such a distinctive view of it. The long first movement can go at a wide range of speeds, but, in practice, either extreme suits it better than a middle way (this is not a political statement), and Barenboim is an extremist at the slow end. Yet the music had urgency because the detail was kept animated while the overall steadiness was firm and full-toned, and increasingly ruthless in impact.

So, it continued with an ultra-slow, intense Marcia funebre, more lament than funeral march; a serious Scherzo, full of character in the horns' accents and phrasing; and an imposing finale with a hymn-like climax, still too urgently expressed to sound inflated. Encores followed of works by Schubert and Rossini, the players enjoying the chance to show some pace and flair. Indeed, most of them looked amazed at the unreserved welcome that the Proms audience gave them, while governments equivocate.