COMMISSIONING new sacred and liturgical works is now - commendably - a norm for choirs around the country. But three new commissions in one programme is no mean achievement, and that is what The Sixteen - thanks to the Genesis Foundation, under its chairman, John Studzinski (which has already funded a clutch of exquisite treatments of a text by Padre Pio) - has just achieved with its programmeof three settings of the Stabat Mater at the Grade I listed Hawksmoor church St Luke's, Old Street - roofless from 1960, but now restored as LSO St Luke's - in London.

The works were by one Estonian and two British composers - although one, 28-year-old Alissa Firsova, is the gifted Moscow-born daughter of two admirable former Soviet-era avant-garde composers: Dmitri Smirnov (a William Blake specialist) and Elena Firsova, who came out of Russia just as Communism fell. Firsova's works are increasingly well known. Smirnov's output, admired in Germany, should be performed far more here, in the country of their exile.

The other two were Matthew Martin, not yet 40, who is carving a name as a writer of church music comparable (say) to Gabriel Jackson. He was previously organ scholar of Magdalen College, Oxford, and assistant at Westminster Cathedral, and is now organist of Brompton Oratory and conducts at the Edington Festival - no mean pedigree. The third, from the Baltic States, is 45-year-old Tõnu Kõrvits.

The composers approached Jacopone's 13th-century Latin text in quite different ways: Kõrvits is the only one who sets the lines more or less straight through, though even he omits eight of the 24 stanzas (noted here in Edward Caswall's rather fine Victorian translation).

Firsova, who approaches the music most straightforwardly (and that has an appeal in itself), sets just seven stanzas, three of which use (legitimate) variant texts. Martin sets just six verses, choosing instead to introduce six lines of new text in English, plus a refrain (all in a variant, nominally iambic, but in feeling trochaic metre), composed specially by the Dean of Canterbury, the Very Revd Robert Willis. Martin goes further (he explains) by rooting his piece in the Stabat Mater hymn tune from the Mainz Gesangbuch or Hymnary (here, 1661).

As in the polished William Byrd motets that intervened, Harry Christophers brought all the well-known powers of the ensemble to bear: meticulous rehearsal, fervent delivery, scrupulous attention to the prosody, and ravishing individual sounds melding in a warm and, with these aching stanzas, even sensual whole. Some intervening readings of Blake evoked an atmosphere of flowers and sunlit gardens.

But it was the choir's lucid readings that enabled the new works to flower. The Kõrvits setting was full of interesting contrasted textures: a bass solo, soprano with edgily shifting alto drone, a plaintive and pleading solo tenor, and later upper voices clustering over lower-voice drone, all culminating in an exquisitely engineered resolution. No one could doubt the sincerity and urgency of this word-setting; nor the impressive security of The Sixteen's bass line, sometimes dramatically dropping an octave; or the impact of the (south-east) Estonian folk music the composer has worked into his structures.

The purity of Firsova's unextravagant lines and harmonies recalls, in a very different idiom, those of her mother, Elena, who is however more modernist by instinct - like Denisov, a carver of a new late Soviet, serially conscious impressionism. I was reminded, too, of another Eastern European composer parent, the Polish-born Sir Andrjzej Panufnik, who died in 1991. He would have been 100 this year.

"Several cadences from different eras weave the piece together," Firsova writes; and, indeed, we can perhaps hear echoes of the French - Duruflé maybe - as much of the Renaissance here. Firsova has a telling way of letting single lines break out from the texture, and in a text such as this it can be highly affecting. So were some bell-like patterns near the close. I was not sure Firsova had finally evolved her own style yet: rather, I sensed an engaging and thoughtful musical personality still emerging.

Martin posed perhaps the greatest challenge: he was prepared to be dangerous and unpredictable. His choral Stabat Mater starts from the hymnic, veers into the declaimed, involves lots of moments of calm, pause, and sustaining, makes use of a striking soprano solo in the first interspersed passage "As you in torment to your Son prove true. . .") and some hugely atmospheric pianissimo, in the last repeated refrain, which demanded of Harry Christophers and his 18-strong Sixteen astonishing powers of concentration, delicacy, and restraint. I need scarcely say that it received all three.