Prom 48, Royal Albert Hall, London<br/>Prom 45, Royal Albert Hall, London<br/>Prom 50, Royal Albert Hall, London<br/>T&#234;te &#224; T&#234;te: The Opera Festival, Riverside Studios, London

The big noise at the Proms last weekend was provided by the Simó* Bolívar Youth Orchestra of Venezuela under conductor Gustavo Dudamel, who blew into town like a force of nature and nearly blew the roof off the Royal Albert Hall.

Its story – and indeed the whole development of music education in Venezuela since the inauguration of El Sistema, a new social approach to the teaching of musical instruments – is truly extraordinary.

The Venezuelans' playing was often thrilling. Prom 48 began with a major challenge, Shostakovich's mighty 10th Symphony, in a performance notable for matching the work's intensity, bar for bar. The demonic scherzo – supposedly the composer's private and deeply unflattering portrait of Stalin – was a fiery whirlwind in sound.

They moved on to a streetwise and sexy account of the Symphonic Dances from Bernstein's West Side Story, following it with Latin American specialities in the shape of José Pablo Moncayo's Huapango, Arturo Márquez's Danzó* No 2 and Alberto Ginastera's ballet suite Estancia. To everything they brought inexhaustible commitment and panache combined with sheer joy in making music. Dudamel himself, at only 26, is a conductor of considerable attainment and even greater potential. That he recently landed the job of music director of the Los Angeles Philharmonic says it all.

At encore time the musicians swapped their formal jackets for the Venezuelan national colours, danced, threw their instruments into the air and generally brought a Latin fiesta spirit to the Albert Hall. It was a fun end to an unforgettable and inspiring Prom. We need El Sistema here.

Last week's new music at the Proms included Hans Werner Henze's Sebastian im Traum, given its UK premiere by the BBC Symphony Orchestra under Oliver Knussen in Prom 45, which also included a lucid account of Schoenberg's classic Five Orchestral Pieces, Knussen's own glistening Violin Concerto (with Leila Josefowicz the shiny-toned soloist) and The Rite of Spring. Henze's shadowy, nocturnal Dream of Sebastian harvests the darker, more autumnal colours in his comprehensive palette, echoing the images of decay and dissolution in the Georg Trakl poem that inspired it. The result is beautifully conceived for its forces and made a striking impression.

So did a new piece by John Adams, which he conducted, again with the BBC Symphony, in Prom 50. Dr Atomic Symphony derives from Adams's opera about Robert Oppenheimer and the development of the atomic bomb, which premiered in San Francisco in 2005. Its sequence of four movements takes us from Oppenheimer's laboratory via an intimate reflection of his relationship with his wife Kitty to a final, apocalyptic section called Trinity that deals with the test detonation in the New Mexico desert in 1945. Like a lot of Adams's recent music, the piece is powerfully eloquent in the grandeur of its gestures, with a good deal more development than in his earliest pieces. It's a big statement on a big subject, though arguably more of an offshoot from a major work than the thing itself. For that we'll have to wait until English National Opera's production of Dr Atomic, scheduled for 2009.

But the real problem with the concert, which started with Aaron Copland's Billy the Kid Suite and continued with Adams's Century Rolls, with Olli Mustonen the pristine piano soloist in this sharply elegant homage to the pianola, was Adams's lacklustre conducting.

With its intimate productions and devotion to new works, many of them specially written for tiny resources, Tête à Tête has developed into one of the most indispensable of the UK's small opera companies. Their three-week residency at the Riverside Studios represented the company's most sizeable season to date.

The evening I caught, however, showed Tête à Tête spreading thin material over too long a stretch. The plan was appealing: three operatic chunks, with time to eat a two-course meal in the Riverside's café during the intervals. The starter turned out to be the most substantial, though even this was a work-in-progress. Jean-Philippe Calvin's La Cantatrice Chauve is a setting of Ionesco's absurdist classic play, which has been running in Paris since 1957. It's partly a parody of bourgeois normality. Two married couples, the Smiths and the Martins, communicate (or not) in phrases taken from English phrasebooks. The banality of their discourse contrasts with their alternately prim and hyper behaviour.

Calvin's score – valiantly accompanied by the composer on percussion and Richard Black on piano – sounds promising, attaining a manic modernist equivalent to a hell-for-leather Rossini ensemble. It might well benefit from the full orchestration that is presumably forthcoming. One or two scenes were left out here. Bill Bankes-Jones, who directed the piece, fleshed out the gaps with a spoken narration. The audience was offered two alternative endings, one with live electronics, provided by Stefan Tiedje, the other without. They chose, quite rightly, the electronic one, which added just that extra touch of surrealism to a show that was fast-paced and entertainingly wacky. Jeremy Huw Williams and Alison Bell sang Mr and Mrs Smith, Daniel Norman and Rachel Nichols took on Mr and Mrs Martin. All provided good value.

The evening went downhill after that. The second course, Broken Voices, more of an art installation by Artprojx with music and sound design by Ian Dearden, outstayed its welcome, and had a very 1970s feel to it. And not in a good way. The last bite, studenty Soundscapes, De-Construction and Cosmic Dimension, involved Calvin slicing up fruit, veg and chocolate and feeding them to the audience. Doesn't he have better things to do, like finishing off his opera?

Need to know

Gustavo Dudamel (pictured opposite) began playing violin at the age of 11, in the city of Barquisimeto, which boasts several orchestras and salsa bands (one run by his father, a trombonist). When he was 13, the classical musician and economist Jose Antonio Abreu spotted him during a school visit and invited him to study in Caracas. Abreu had founded El Sistema (the system) in 1975, which brought classical music to poor children from the barrios. It started out with 11 children; they were given instruments, taught to play, and formed into an orchestra. Now 250,000 children are involved, out of a population of 27 million Venezuelans, and undoubtedly innumerable lives have been transformed.

Further listening Beethoven: Symphonies 5 & 7 by Simó* Bolívar Youth Orchestra, conducted by Gustavo Dudamel, Deutsche Grammophon