Irish Timesreviewers were at a recent concert by RTÉ National Symphony Orchestra and a performace of A Numberat the Peacock Theatre.

Chang, RTÉ NSO/Hermus

NCH, Dublin

Smetana - Bartered Bride overture. Dvorak - Cello Concerto. Suk - Asrael

Friday's programme from the RTÉ National Symphony Orchestra was an all-Czech affair.

Visiting Dutch conductor Antony Hermus, making his debut with the orchestra, laid his cards on the table right from the start.

The bustle of Smetana's Bartered Brideoverture was never allowed to descend into dry chatter.

The presentation was forward and full, the manner hearty, even boisterous.

The soloist in Dvorak's Cello Concerto was Korea's Han-Na Chang, who surprised the world by taking the top prize at the Fifth Rostropovich International Cello Competition back in 1994 at the age of 11.

She produced a huge sound in the Dvorak, digging into the strings with an often biting rasp, and riding the orchestral climaxes with impressive aplomb.

Her musical approach may have been on the melodramatic side, but there was never a dull moment, and the grand emotional sweep of her playing was always persuasive.

Josef Suk's AsraelSymphony began life as a work in memory of his beloved teacher and father-in-law, Dvorak.

But the death of his wife, while he was still at work on the piece, caused him to replace the originally-planned finale with a pair of movements constituting an even more painful memorial.

The tragic jolts seem to have catapulted Suk into a new compositional mode, more harmonically complex and more dissonant than his earlier work.

The symphony, named after Islam's angel of death, is a late-romantic piece in the grand manner which holds the attention through its sheer ardency.

Hermus' sustained and passionate vision propelled the players of the NSO to match the composer every step of the way. - Michael Dervan

A Number

The Peacock, Dublin

If the sins of the father are visited on the son, what chance does the son's clone have?

In Caryl Churchill's fascinating play, A Number, which teases open bioethical concerns the way a switchblade teases open a gut, a man confronts his father with the recent discovery that he is not unique, but a copy.

In fact, as one of several clones, he barely even qualifies as a limited edition: "A twin would be a shock," he says, "but a number . . ."

Beginning with such urgency, Churchill's intense and elliptical play tumbles through fractured sentences and teasingly ambiguous developments, haring along without elaboration or explanation.

Details begin to emerge: Bernard is not Salter's natural-born son, but rather a clone of an original who died.

"Another child might have been better," suggests Stuart Graham's Bernard 2, nonplussed.

"No," replies Alan Williams' eerily sedentary Salter, "I wanted the same."

Like most things in Annabelle Comyn's deliberately unembellished production (with an equally minimal design from Brien Vahey), this is only partly true.

Salter wanted different. Across five conversations, and without ever leaving his armchair, Williams visits the repercussions of his actions: those of a father who neglected his first son - and who then tried to start over.

By the time the "damaged" original appears, still very much alive but now an unblinking psychopath, it seems Graham has the trickier task, playing genetically identical but psychologically dissimilar characters.

Yet Williams's grave patriarch undergoes as many shifts, his dubious efforts to reform leaving him unable to divert his destiny.

Both sons will end up hating him, but for distinct reasons, and though the science at issue is new, the irony is ancient.

This tragedy seems less genetically encoded than dictated by the Fates.

Not that Comyn chooses to hack any simple path through the play's wilderness of concerns.

Staging it in the traverse (which now seems to be The Peacock's default setting), she instead deposits us right in the moral tangle of the play, with no option but to think our way out.

Much of that invigorating engagement will peak with the final encounter, between Salter and Michael Black, yet another clone who has grown up unaffected, untroubled and unexceptional.

Easygoing to the point of banality, Black is somehow Graham's most convincing creation, a model of "damaged uniqueness".

But the questions asked of him are likely to snag our own minds, and the effort to define his uniqueness may yield countless responses from every audience - none of them identical. - Peter Crawley