Prom 52: Gruber/Weill/Eisler <br/> Prom 53: Turnage/London Philharmonic Choir And Orchestra/Jurowski, Royal Albert Hall, London

The rebel tonalist H K "Nali" Gruber is one of the few genuine funsters contemporary music has thrown up, so it was strange his Prom opened with a new work which was no fun at all. If his much-bruited "Hidden Agenda" had one, I couldn't find it: it just started, grew a bit, then stopped.

From that point on, however, Gruber's self-conducted concert with the BBC Singers and BBC Symphony Orchestra was riveting. Bertolt Brecht's faux-naif political poetry was tailor-made for musical treatment by his friends Kurt Weill and Hanns Eisler: the series of songs which Gruber selected packed an extraordinarily gamey punch. "Uber das Toten", "about the dead", became a ghastly, out-of-kilter chorale; the savage dissonances in "Die Legende vom toten Soldaten" undercut the chirpy tone of Brecht's tale of the corpse who became the star performer in a military march. Finally, Gruber gave a stunning performance in his popular "Frankenstein!!". It wasn't just the paper bags burst and flung into the audience. It was the lovable madness of the whole charade.

The centrepiece of the following night's Prom, conducted by Vladimir Jurowski, was a characteristically limpid performance of Prokofiev's Second Piano Concerto by Nikolai Lugansky, but it opened with a forbidding new work by Mark-Anthony Turnage. Turnage's normally fecund imagination was held in check by his rigorous intellectualism: turning private grief into a public statement in "A Relic of Memory". Later, the London Philharmonic Choir were reinforced by the Philharmonia Chorus for a magnificent performance of Rakhmaninov's "The Bells", which soprano Tatiana Monogarova's gorgeously floated high notes carried triumphantly to the heavens.

BBC Proms to 9 September (020-7589 8212; www.bbc.co.uk/proms)