Standing ovations. Spontaneous genuflections. A we-can-change-the-world lecture. This must be what's it like to live in a Communist state. Funnily enough, the Simón Bolívar Youth Orchestra, who we were saying goodbye to last night in the final concert of their four-day Southbank residency, already do. I'm not a supporter of El Sistema, the body which gave birth to this youth orchestra.

At the Royal Albert Hall one summer evening in 2007, a teeming ensemble of young South Americans served up a BBC Prom that is the most YouTubed classical concert this side of the Three Tenors. Under the baton of the compelling Gustavo Dudamel, an all-dancing, all-shouting account of “Mambo” from West Side Story has become the roof-raising sign-off of the Simón Bolívar Symphony Orchestra of Venezuela, who last year dropped the word Youth from their name.

The repertoire of the OAE is creeping away from the 18th century and into the 20th with such unashamed eagerness, it wouldn't be at all surprising to see them throwing up an urtext edition of "Hit Me Baby One More Time" in a few seasons. Last night, we got 20th-century French impressionism, including a work that was premiered in 1933. Some might call this expansion into the last century bold. Others greedy.

It's easy to forget exactly how successful Norah Jones is, but with over 50 million records sold, she is a modern success up there with the Jay-Zs of this world. To see her come on stage last night, though, you wouldn't have known it. There were no fireworks, no build-up of drama, no crazed intro tape, no MC on stage to announce her entrance, just a band and singer walking on stage to play.

There comes a point in almost every great soprano’s career when she tells the world that Tosca, the Marschallin or Isolde be damned: what she wanted to sing all along was The Great American Songbook. This announcement tends to be made - how shall I put this? - later rather than sooner. In Jessye Norman’s defence, in 1987, just five years after her landmark, ultra-luscious recording of Strauss’s Four Last Songs, she recorded a disc of Gershwin, Richard Rodgers et al.

Two more contrasting pianists than Yuja Wang and Martin Helmchen would be hard to find. To move within 24 hours from the glittering assault of Wang’s technique to the restrained, almost introverted, Helmchen is an exercise in extremes, and one that left me yearning, Goldilocks-style, for a soloist neither too hot nor too cold, but just right. Dvořák’s Piano Concerto may have been a sober affair, but the London Philharmonic Orchestra and Vladimir Jurowski bid farewell to their Southbank season in a blaze of Central European passion and music by Suk and Janáček.

Let no one tell you that Chinese pianists can't play with passion. Yuja Wang ran the full gamut of emotions in last night's Queen Elizabeth Hall recital from the tender to the rhapsodic. But mostly she channelled her energies to delivering some of the most colourfully explosive playing I've heard for ages. 

This has to be the only music festival I've ever been to where two vacuum cleaners were on standby in case the star performer conked out. But that's what happens when your star performer is a player piano - they seem to run on Hoover tubes. With 11 concerts and one film in two days, this celebration of American maverick Conlon Nancarrow was London's alternative marathon. One that was no less eccentric, exhausting or adrenalin-generating (though much less running-based).