A thousand twangling instruments: Bayan Northcott surveys the sonorous heritage of Shakespeare's The Tempest in the light of a new recording of Sibelius's complete incidental music

A LATE comedy of forgiveness? An allegory of artistic isolation? An indictment of Western colonialism? A myth? The more one looks at the tightly structured yet vastly ambiguous text of The Tempest, the less Shakespeare's last completed play can seem quite to add up. And what are musicians to make of a poetic drama that invites the involvement of their art more than almost any other, and yet - as over 300 years' worth of attempts have demonstrated - so subtly resists setting as a whole?

After all, the text as printed in the first folio of 1623 includes verses for seven songs or song-fragments - for Ariel, Caliban, and the drunken butler, Stephano. Then there are the dances of the 'strange Shapes' mocking the royal party with a phantom banquet and the masque Prospero presents to Ferdinand and Miranda, which require more continuous sequences of numbers, plus some half-dozen briefer cues for 'solemn music' and so on. Indeed, it is difficult not to imagine music haunting any number of other passages, from Prospero's various spells to Caliban's evocation of those 'thousand twangling instruments'. And while little seems to be known about Jacobean sound effects (did they play music for storms and hunts or simply rattle barrels and make barking sounds off?), composers were soon enough to evolve suitable sonorous imagery.

Of the play's earliest productions - at Court in 1611 and again the following winter - the only likely music that survives comprises settings of 'Full fathom five' and 'Where the bee sucks', plus a single, tenuously ascribed dance, probably by the royal lutenist Robert Johnson. But just as The Tempest has proved an almost inexhaustible source for subsequent writers, all the way from Fletcher's play, The Sea Voyage, of 1622 to Auden's wonderful verse and prose commentary, The Sea and the Mirror, of 1943, so it has inspired an extraordinary range and variety of music. And not only between the innumerable settings of Ariel's songs - though even among post-war versions of 'Full fathom five', the crypto-serial intricacies of Stravinsky's solo-setting of 1953 could hardly sound less like the mystic choral chimings of Vaughan Williams two years before.

Already by 1667, Dryden, Davenant and a bevy of contemporary composers were busy updating the play as, in effect, a Restoration musical - with extra production numbers, Ariel acquiring a girlfriend and what have you. Periodically revamped, this farrago tottered on for over a century. One particularly resplendent new musical version was long believed to be the last major work of Purcell, though it is now thought to be later and probably by John Weldon. While the English tradition of Tempest song- setting continued through the 18th century into the 19th - from Arne and Boyce to Sir Henry Bishop - the play turned up in Vienna in the 1790s as a full-blown libretto entitled Die Geisterinsel, originally intended for Mozart but set no less than four times by lesser composers in the next few years.

The 19th century brought its own genres to bear on Shakespeare's text with extensive incidental music by the young Sullivan and concert fantasias by Berlioz and Tchaikovsky. Yet it has to be conceded that none of the operatic versions, from Halevy and Fibich in the later 19th century to Frank Martin in 1955 and the elaborate post- modern treatment by the American composer, John Eaton, staged at Sante Fe in 1985, seems to have taken. Where the play has exerted an influence on more recent music dramas, it is curiously oblique: in the Tempest-based group therapy games played by Tippett's neurotic moderns in The Knot Garden, or through reverberations of Die Geisterinsel and The Sea and the Mirror as Berio's stage-director protagonist, Prospero, dies in Un re in ascolto. It is interesting to note a similar, elaborate indirection in more recent films by Derek Jarman and, latterly, Peter Greenaway's Prospero's Books with music by Michael Nyman. And though Ligeti's promised setting may yet prove The Tempest an operatic going concern, it seems an awful long time in coming.

But then, when Andrew Porter deleted Shakespeare's more evocative passages from his libretto for Eaton, in order to leave something for the music alone to do, he was surely putting his finger upon the problem.

It is not just that the range of allusion, the quality of the language itself is so directly musical, but that the whole underlying form and flow of imagery so strangely anticipates and parallels the procedures of through-composed opera. In the end, the use of music in The Tempest probably has to remain highly intermittent to exert optimal effect. Theatrical economics in more recent decades have generally restricted incidental music to small groups, such as the wind ensemble with percussion, harpsichord and harp that Tippett used for the Old Vic production of the play in 1962, or electronic effects, pioneered a couple of years earlier in Peter Brook's Tempest at Drury Lane with simple musique concrete sounds - if memory serves - by Brook himself. But there does survive one truly grand incidental score in the tradition of Mendelssohn's A Midsummer Night's Dream and Grieg's Peer Gynt from the era when drama companies, at least under festival conditions, could still call upon full symphony orchestras.

Sibelius had just launched his Seventh Symphony when he was commissioned by the Royal Theatre in Copenhagen at the end of 1924. The conditions were lavish and accommodating: Shakespeare's opening scene, for instance, was to be dropped so that full attention could be concentrated on Sibelius's storm prelude. The composer in turn took the greatest care in the disposing of his large forces, with sundry voices and players behind the stage, plus harp and harmonium poised above.

The music, which somehow manages to unify the most diverse styles - from Baroque, by way of 19th-century salon to grindingly modernist - in a remotely poetic ambience, is best-known from the Prelude and two Suites he arranged and published subsequently in 1927, themselves comprising some 40 minutes of music. But the original score, with its many extra episodes, now recorded complete for the first time by soloists with the Lahti Opera Chorus and Symphony Orchestra under Osmo Vanska, runs to no less than 67.

Those who know the Suites well will be fascinated by the way Sibelius often transformed his theatrical scoring and assembled movements from quite different sections of the incidental music. The long, serene horn calls of the 'Chorus of Winds' which opens the Second Suite were originally for off-stage chorus, while its benign coda for strings comes from near the end of the incidental score, at the point where Prospero relents and forgives. There, however, it is preceded by an extended orchestral tutti of quite extraordinary dissonance representing his struggles of conscience, only a short section of which survives in the First Suite. And Sibelius was to find no further use at all for perhaps the most remarkable moments of the original score in which Ariel's entrances and exits touch off sudden, complex bursts of orchestral activity lasting some 15 seconds before evaporating in harp glissandi. Since he never wrote anything else quite like these, it is a pity their detail gets blurred in the spacious, somewhat recessed acoustic that the BIS engineers have chosen to enhance the atmosphere of the score as a whole.

The storm music itself, of course, survived both as a separate Prelude and, in a slightly different form, as the finale to the First Suite - and remains sui generis. Auden once categorically asserted that 'Music cannot imitate nature: a musical storm always sounds like the wrath of Zeus'. If one thinks of the merry billows that represent 'The British Ocean in a storm' in Purcell's King Arthur, the rampaging trombones of Rossini's William Tell or even the pounding dance of the waves in Peter Grimes, one has to concede that sound and fury remain within the grip of purely musical procedures. But Sibelius's awesome stretch of tritone-doubled chromatic waves against whole-tone skirlings - a minimalist process blown up with maximalist force - edges so close to onomatopoeia, it has to be granted the great exception.

Sibelius's incidental music to 'The Tempest', Op 109, recorded by the Lahti SO/Vanska, is on BIS CD 581