Music: The numbers game that doesn't add up

The Dramatis personae of Schoenberg's Moses und Aron reads like the record of a police raid - or perhaps an adult version of "On the Twelfth Day of Christmas". Four naked virgins, three elders, one naked youth, 12 tribal leaders ... the list runs on in graphic testimony to the composer's numerological obsession. And when you add the Act II scenic requirement for camels, asses and horses, and a chorus self-immolating, jumping off cliffs, or otherwise sharing what the libretto calls an "orgy of destruction and suicide", you appreciate why this epic opera-oratorio is a piece more talked about than performed. The instructions are like Wagner's for The Ring: so over-specific that the author could only have intended them as theatre of the mind. And that, no doubt, is one reason why Moses und Aron was never finished. The project lived with Schoenberg for 20 years, but he only completed two of the three acts.

It follows that stagings of Moses und Aron are rare, and even concert performances constitute events - not least because of the vocal demands on the chorus. The score is the ne plus ultra of Schoenbergian serialism, its formidable complexities, derived from a single note-row, making no concession to human falli- bility in either performers or listeners. Only nerves-of-steel conductors need apply.

The steel nerves this week at the Festival Hall belonged to Christoph von Dohnanyi, directing the Philharmonia Orchestra; it was Dohnanyi's first appearance with the Philharmonia since news broke that he will become its chief conductor next year. The appointment is no surprise: the Philharmonia have courted him for ages, and he's been playing hard (ie expensive) to get. But then, he is a catch. As music director of the Cleveland Orchestra since 1982, he could reasonably be said to wield the most prestigious baton in America. His repertory tastes may tend toward the chastening and cerebral, but he delivers them without the chill that once froze Boulez out of the New York Philharmonic, and his arrival at the South Bank (where the Philharmonia are now jointly resident) can only bring to that flailing institution a touch of desperately needed class.

Moses und Aron was, one hopes, a glimpse of what's in store. Dohnanyi has done it with the Philharmonia before, in one of the orchestra's Paris residencies, and so far as anything in Schoenberg's music can be described as beautiful, it was. When Georg Solti recorded Moses for Decca some years ago, he told his assembled forces to play it like Brahms and manifest the debt that Schoenberg always, even at his most rigorously serial, bore to Viennese late Romanticism. I don't know what Dohnanyi told the Philharmonia, but they played like angels, cherishing the sense of line and sustaining as rich and radiant a tone as possible in the spongy RFH acoustic. With epic Cecil-B-de-Mille conviction from Aage Haugland's Moses, and lighting effects that threw the libretto-following audience into a frenzy until they realised there were surtitles, it sustained a sense of drama and proclaimed the music's power.

That said, it still didn't persuade me that Moses is the masterwork Schoenbergians insist. If this were real theatre- music it wouldn't throw away so many of its key dramatic opportunities: Aaron's miracles, for example, are narrated with dutiful understatement; and whatever Schoenberg's mind made of the "orgy of destruction", his pen signally failed to reproduce it. In effect, the problem of Moses is the problem of its central character: a prophet earnestly attempting to communicate lofty abstractions to a people who need brazen images to foster their belief. Aaron - putatively God's PR man, set by Schoenberg as a lyric tenor - offers them the Golden Calf. But Moses will accept no compromise. Schoenberg, we know, identified his own efforts to declare a tough new abstract law of music with the Messianic stance of Moses. Pierre Boulez, in a 1974 essay, dismissed Schoenberg's Messianic affectations as "irritating". He had a point.

Beethoven piano-sonata cycles are big undertakings, associated in Britain with big names like Alfred Brendel, Richard Goode and (soon to start at the RFH) Maurizio Pollini. But a younger, less established name arrived at the Wigmore Hall this week with a cycle of his own: the Chilean pianist Alfredo Perl, whose decision to squeeze the project into seven nights makes for some extremely full programmes. On Tuesday we began with Nos 1, 11, 24, 27 and 21 (the sequence isn't chronological) - maybe too much, but impressive. Perl's playing has a blunt-edged stubbornness about it: not enough legato, sparing with the pedal. But it's clean, transparent, honest playing, that delivers the problems as well as the pleasures of this music in direct and forthright terms. Where the writing is awkward or the harmonic progressions bizarre, you feel the discomfort, viscerally. When it takes wing, you fly. The exposure is unsparing - he makes the Wigmore Steinway sound like a fortepiano - and the control of dynamic excellent. It may not come loaded with the weight of experience of a Brendel, but this playing has a virtue of its own that promised well for the rest of the series.

The virtues of the Danish National Radio Symphony don't quite merit inclusion in the "Great Orchestras of the World" series, in which it appeared at the Barbican on Monday. It isn't the Berlin Phil. But its new (German) chief conductor, Ulf Schirmer, has been driving it to serious achievements, such as the Lulu reviewed from Copenhagen on this page a few weeks ago; and although the new, uneventfully disembodied Bent Sorensen symphony that opened the programme didn't offer much chance to shine, Nielsen's Fifth, which followed, did. With its concerto-profile role for antagonistic snare-drum, this is one of the most strikingly individual sym- phonies of modern times; and if the DNRSO players didn't wholly encompass its visionary qualities, they got its muscularity and toughness. For those who missed it, the orchestra are currently engaged in a Nielsen recording cycle that includes the opera Maskarade. There's a glut of glorious Nielsen on the market these days, but not much of it from Denmark.

Time for the home team to reassert itself.

Alfredo Perl: Wigmore Hall, W1 (0171 935 2141), Tues.