New Zealand Symphony Orchestra at Auckland Town Hall

Michael Norris' Heavy Traffic is a concert opener to die for. The latest NZSO commission, this short piece for contra-bassoon and orchestra promises road rage, tailgating and lane changing, and achieves all three, musically speaking, with the deftness of an Indy 600 champion.

There's some respite from the hyperenergy - a gentle passage introduced by a shiver on muted brass - but for the most part it's a darting, pointillist frenzy, effortlessly revved into life by soloist Hamish McKeich and the NZSO.

The celebrity soloist of the weekend is Julian Lloyd Webber. Friday's Elgar Concerto is a very deliberated affair, with poetry first and rhetoric second.

From the first bursts of cello melody, there are many individual touches along with moments of intense reflection.

If there is too much rubato in the slow movement, then the cellist is happy to be drawn into more vigorous rhythms later by James Judd and the orchestra.

On Saturday, Tchaikovsky's Rococo Variations is remarkable for the freedom of Lloyd Webber's conception, growing from a theme that is like a gavotte in gossamer.

The soloist constantly looks right and left for engagement with the musicians around him, until the final variation picks them all up with a whirlwind of virtuosity.

Encores are high-minded. On Friday, there is a lyrical outpouring from Malcolm Arnold; on Saturday the pizzicato "Serenata" from Britten's First Cello Suite, tantalisingly non-Western in its sound.

Both concerts present mammoth specimens from the late Romantic storehouse, giving Judd the opportunity to flaunt his expertise in this territory.

Zemlinsky's The Mermaid is a 45- minute orchestral soul-baring. It's not every composer who would work through his frustrations after a thwarted love affair by turning to a Hans Christian Anderson fairytale.

Stylistically, Zemlinsky is conservative for his time and often struggles to achieve the emotional power of a Mahler.

The NZSO is in splendid form, but too often the composer's technique of building to a climax, pulling back and then revealing a grotto of chamber music-like enchantment becomes a cliche. There are a few too many Korngold sunrises, and the incessant quotation of a theme that seems to have slipped in from Tchaikovsky's Fifth becomes irksome.

Friday's Zemlinsky is followed by Mahler on Saturday - the Tenth Symphony, in the Deryck Cooke reconstruction, reveals a composer with more to say.

Judd and his players catch every aspect from the utter anguish of the opening Adagio, the bitter-sweet reflections of the second, premonitions of Shostakovich grimness in the fourth and the wrench of emotions that chart the final Adagio.

After an hour, stamina seeps a little, particularly in the violin's upper register, but this transcendent performance more than vindicates Cooke's judgment of the work, 46 years ago, as "the near-realisation of a final, spiritual, victorious masterpiece".

When: Friday May 26 and Saturday 27 May