Eric Whitacre – less a composer or conductor, more a global choral phenomenon. Just the mention of his name in last night’s concert introduction drew whoops and wolf-whistles from the crowd, certainly not a reaction you tend to get for Beethoven, Boulez or Cage (though perhaps the latter gets a silent cheer). Like or loathe the hype that surrounds Whitacre, there’s no denying his role in popularising choral singing, nor the pure American genealogy of his style, which we can trace back through Morten Lauridsen and Randall Thompson to Bernstein and even Copland.

In a festival season as long as the BBC Proms there are always going to be some longueurs, weeks where the orchestral playing is more adequate than astonishing. Get stuck in one of these and it’s easy to start doubting your ears, to wonder whether six weeks of orchestral assault have dulled them. Then you hear an ensemble like the Gustav Mahler Jugendorchester. A youth orchestra in name alone, there is nothing callow about this elite group of young musicians, who last night under Daniele Gatti coaxed and wrung the Royal Albert Hall audience into ecstasy upon ecstasy.

After the all-singing, all-dancing, all-helicoptering brilliance of Stockhausen Mittwoch aus Licht, the dry routine of an opera in concert didn't seem a very enticing prospect.  That's the problem with this year's Cultural Olympiad. We're becoming very spoilt by it. What should have been a mouth-watering prospect - a fantastic cast performing a great opera - suddenly began to feel run-of-the-mill when compared to the once-in-a-lifetime event that was Mittwoch. But my concerns were short-lived.

Sir Peter Maxwell Davies’ Ninth Symphony, completed in 2012 and heard in London for the first time in this concert, is dedicated to the Queen on her Diamond Jubilee. Those are not words to strike eager anticipation into my heart , though I’m happy to say that being Master of the Queen’s Music doesn’t appear to have dulled the composer’s powers in the way the equivalent title seems to nobble poets. Indeed, the dedication is merely that, and the work is no winsome tribute.

It is a rare treat for Londoners to have the CBSO with Andris Nelsons in town, and the Albert Hall was, if not fully sold out, then certainly well stocked. It would be fair to assume that the main draw was Shostakovich’s giant and much-debated Leningrad symphony after the interval; but first up was Glinka’s Ruslan and Lyudmila overture and the UK premiere of Emily Howard’s Calculus of the Nervous System.

One chocolate bar, OK. But eating three in a row? Is that altogether wise? Some may feel the same about a concert containing three symphonies by Vaughan Williams: a third of his output in the form. Even the most committed lover of this visionary and still under-appreciated British composer might worry a little at the prospect, as we might at a heavy night of Beethoven or Brahms. Each symphony, to be sure, is coloured with different forms and emotions. But similar harmonies, intervals and rhythmic figurations still recur. "Variety is the spice of life" isn’t a popular saying for nothing.

It may be the power of suggestion, but there was distinctly laid-back vibe at the packed Royal Albert Hall last night. Clapping between movements (and this was an audience never knowingly under-clapped) wasn’t greeted by the any of the usual hisses, and when a latecomer clattered down the entire length of stalls steps before the Largo of Dvořák’s Symphony No 9 she drew only the most indulgent of laughter. The Brazilians had arrived, bringing with them a warmth that extended well beyond the stage.

Shamefully, the Albert Hall was just over half full for this impeccably programmed celebration of that most "youth" of ensemble types, the Wind Orchestra and Brass Band. The air of a glorified school concert was blessedly absent throughout (except for the slightly patronising between-movement applause), which meant that both of these tack-sharp outfits could present their selections seamlessly and without fear of the usual "but they're so young!" silliness in an exclusively British programme.

On the one hand, having a massed brass and percussion section (I counted 16 timpani) in front of three massed choirs lent this evening an air of fantastic anticipation. Boom and crash and honk: that’s what we wanted. On the other hand, it was immediately a measure against which anything less than deafening volume would be harshly judged. All reminders of the potential clout were constantly there, embodied by bored-looking trombonists counting their hundred bars’ rest. The key here is to make those quiet moments magical – and that didn’t quite happen this evening.

A motley crowd at Cadogan Hall on Saturday afternoon: new music aficionados and interested parties; general music lovers; some passing trade; tourists; one dad with a young boy of six or seven. Heaven knows what the latter made of the dissonances, dislocations and heated laments summoned forth by the intrepid performers in this invigorating concert, dominated by the creations of some of the more challenging composers among contemporary Brits.