On the blogs some of the comments about the premiere of John Tavener’s latest work were almost apocalyptic in their fury. “May God have mercy on their souls,” was one Catholic activist’s post, though that fervour didn’t quite transmit to the small protest outside Westminster Cathedral, the site that some felt was so inappropriate for The Beautiful Names, Tavener’s setting of the 99 names of Allah — a commission from the Prince of Wales, who attended this performance.

It’s strange that the contemporary composer who has probably done the most to champion Christian spirituality in his work should spark such a controversy. For John Tavener, music is faith, and if the thought-world of his latest work — fascinating, beguiling and flawed — extends beyond his own personal allegiances, isn’t the Cathedral’s decision to welcome Tavener’s ecumenical impulse a sign of a tolerant and forward-looking institution?

Whether Tavener has bitten off more than he can chew here is another matter. Nine sections of 11 names each, each labelled according to a Hindu, not an Islamic, theological system, are bound together in a complex system of percussive punctuation — American Indian drums, Tibetan temple bowls — and elaborately constructed musical symmetries. The chief declaimer is the tenor John Mark Ainsley, both sparking off and feeding off the BBC Symphony Orchestra and BBC Symphony Chorus, with a string quartet making tender contributions from the gallery and the Choir of Westminster Cathedral adding to the panoply of namers and accompanists.

It’s still an immense task to inject that all-important Tavener sweep into such a bitesize and monothematic text. Cannily, Tavener lulls you in slowly, giving each name a self-contained musical chunk before starting to bind them together in longer, more expressive phrases. Some of these opening paragraphs are stunning — the glorious sunburst of Allah the Creator (Al-Khaliq) rivals the start of Haydn’s Creation in its joyful energy — others seem more like cautious building blocks.

But just what are they building to? In the score, Tavener’s intentions are clear: passages are hyperbolically marked “with cosmic energy”, or “with infinite tenderness”, but what you hear from the unbelievably hard-working chorus doesn’t always match up. Too often the chorus slip into wispy exhalations — Tavener calls it the Sigh of Sadness — an overused conceit, while by far the best of the orchestra is heard in the inventive interludes between the recitations, in the jousts of trumpets and trombones or lush string sonorities which JirÍ Belohlávek conducted with almost Wagnerian urgency.

As we approach the 99th name Ainsley sings with even more fearless rapture — but The Beautiful Names ends in curiously subdued rather than all-embracing fashion. At the end of this journey, the pieces of this giant spiritual jigsaw still don’t seem to fit together, but many of them do glint with astonishing beauty.

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