Semele, Theatre Royal, Glasgow

The best ideas are those that make you wonder: why did nobody think of it before? Handel's Semele is half-opera, half-oratorio. There is action and reaction between dramatic principals; also choruses, some of them fugal and monumental.

The best ideas are those that make you wonder: why did nobody think of it before? Handel's Semele is half-opera, half-oratorio. There is action and reaction between dramatic principals; also choruses, some of them fugal and monumental.

So why not begin the thing as an oratorio, with the chorus in dinner jackets, seated on rows of stacking chairs, and gradually mutate into an opera, insinuating costume and scenery as the action develops? John La Bouchardière's production for Scottish Opera (SO) was one of those simple ideas that come off perfectly. When Jupiter interrupted the opening scene with a thunderclap and everybody grabbed their chairs and ran, you felt a true theatrical moment.

Thereafter, the formula was to present sumptuous baroque costumes against back-projections of planets, galaxies, limitless skies. It was spectacular, even though the audience sometimes laughed in the wrong places; the cloud from which Semele sang her glorious air, "Endless pleasure", turned out to be an immense white pillow on fly-wires; a fatuous vision.

But one's scruples were overwhelmed by the sheer standard of the performance. Christian Curnyn made the SO orchestra sound like a specialist ensemble; the little hand-timpani giving a nervous thrill. His tempi were fast enough to propel the singers through their roulades like running deer, and poised enough to colour the slow airs with lofty sentiment.

And what singers. Lisa Milne, in the title part, has become the complete baroque soloist. She has all the dazzling coloratura (though her part in the big final duet was taxing even for her), together with the creamy purity required for Handel's particular vein of liquid, caressing tunefulness. It was a pity the viola da gamba sounded so stale in "Oh sleep".

The composer made an accidental concession to 21st-century taste by having a tenor, not a castrato, for the leading male role of Jupiter. Jeremy Ovenden must be one of the few modern singers who can encompass the prodigious virtuosity of the Act 2 air, "I must with speed amuse her", and then touch the heart with the chaste lyricism of "Where'er you walk".

The part of Athamas was weak, on the other hand, because Handel gave it to a high voice and it had to be transferred to a counter-tenor, Arnon Zlotnik. He sang with taste, but the lower register was vague.

Never mind; his duet with Ino (the mezzo, Susan Bickley) came off because she, too, had a soft-edged lower range. This artist doubled as Juno. She acted with such wit and charm that you forgave any vocal limitations. Kate Royal was an expressive Iris; Michael George a heavyweight Somnus.

SO may be under a political cloud, but they still show their ability to present a fine performance: stylish; sophisticated; inventive. They are a vital feature of British culture. They need a Maecenas, perhaps, to keep their flag flying.