Prom 71: Tetzlaff/St Louis Symphony/Robertson, Royal Albert Hall, London ***/ Prom 72: BBC Singers and SO/Curran/Adams, Royal Albert Hall, London ****

Christian Tetzlaff is a wonderful violinist who likes to break new ground, and for Beethoven’s Violin Concerto he was going to play cadenzas he himself had arranged from the cadenzas Beethoven had written for his piano version of this work. But Tetzlaff’s real novelty turned out to be something else.

From his opening upward flight his sound was pure and expressive as usual, and David Robertson brought down the volume of the St Louis Symphony Orchestra far enough for him to shine through.

Tetzlaff used the key-shift before the development section to intensify the mood, drawing the ear in with a sound which, though on the edge of audibility, was finely focused; the first-movement cadenza was a curiously ghostly affair which briefly incorporated a military march. In the Larghetto he soared gracefully aloft with a fine thread of melody, but when he employed that same sound for the exuberant Rondo it was suddenly all too much: even his final flourish - a typically robust Beethovenian gesture - was a mere dainty whisper. There was no juice, no oomph, nothing heroic in this performance. Magnificent, as the French general said of the charge of the Light Brigade, mais ce n’est pas la guerre.

Prom 72 brought one of contemporary opera’s undisputed classics, ‘Nixon in China’, with its composer John Adams on the podium. Since the staging was minimal - a few back-projected images, red flags for the chorus to wave, a scarlet dress for Pat Nixon, subfusc grey for everyone else - this was in effect a concert performance, and one realised how integral Peter Sellars’s mise en scene had been to the work’s initial success in 1987. Adams may have found a new idiom - quite different from those of Reich and Glass - but he wasn’t very interested in orchestration: his real interest lay in games with rhythm and tempo. Meanwhile his librettist Alice Goodman’s twin preoccupations were the minutiae of this little bit of history, and her particular brand of lyric poetry.

That this concert worked was thanks to superb performances all round: from the BBC Singers and its Symphony Orchestra, and from outstanding solo turns by Kathleen Kim, Alan Oke, Gerald Finley, Robert Orth, and Jessica Rivera.