Large churches are hardly ideal places to be on the coldest nights in winter, but, on 11th December in St Leonard’s, Shoreditch, the atmosphere was festive enough to make up for what the air lacked in temperateness. Forty years ago, to the very day, The Hilliard Ensemble performed its first concert, and it has been at the forefront of innovation and excellence in musics ancient and modern ever since. This concert was a celebration of The Hilliard Ensemble, its wide-ranging repertoire and its members’ – and alumni’s – talents. Hosted by the slightly younger but equally eclectic Spitalfields Music, as part of their Winter Festival, it was a seasonal affair in which the Christmas journey from Advent through to Epiphany was charted in music spanning a millennium. Thus the birthday boys wrapped their full house up in a rich musical tapestry, ensuring that the cold stayed out on the East London streets, and St Leonard’s became awash with warmth.

The first half was brilliantly structured around the great O Antiphons of the medieval Advent liturgy. These seven short texts – all beginning by invoking Christ using a different Messianic title preceded by the word ‘O’ – were each sung before the Magnificat in Vespers services in the week leading up to Christmas day. Members of The Hilliard Ensemble past and present joined forces to sing these monophonic chants: elegant, powerful and somewhat mystical in their simplicity, language and history.

The concert began, however, with the group’s current members performing music by the 12th-century Parisian composer Pérotin. Viderunt Omnes is a four-part work in which one singer holds an elongated plainchant melody and the others intertwine in incredible, florid, jubilant melismas. These uncanny, complex musical passages finally open out onto equally remarkable cadences involving crunching discords, resolving onto airy consonances before the rest of the phrase is sung to unison plainchant.

The link between the O Antiphons and the Magnificat was made explicit by the interpolation of passages from Tomas Luis de Victoria’s Magnificat secundi toni. In this piece Victoria uses the technique of falsi bordoni, setting alternate phrases to plainchant whilst creating exquisite four-part polyphony for the others.

Other interpolations into the O Antiphon exploration included Josquin des Préz’s stunning Ave Maria, Pomponio Nenna’s O magnum Mysterium and an Exordium Quadruplate from the Codex Specialnik, a late-15th-century Bohemian manuscript. This polyvocal motet had all four singers reciting their own specific text simultaneously, creating an overwhelming but exciting texture, bizarrely reminiscent of the soundworld of Pérotin.

Throughout the first half, it was the existing Hilliard members who did most of the singing. Countertenor David James thus had to shoulder the responsibility for providing the top line. This he began exceptionally beautifully, but towards the end the strain began to tell as he held back on the highest passages. At the other end of the spectrum, baritone Gordon Jones also struggled occasionally with the lowest bass notes.

The Hilliard alumni came further to the fore in the second half, contributing an added richness to William Byrd’s glorious six-part motet Descendit de coelis and John Sheppard’s Laudate pueri Dominum. The polyphonic extravagance of the former was followed by an exquisitely intimate tenor duet, the medieval Christmas carol Lullay lullow. This in turn contrasted with Britten’s Canticle IV: Journey of the Magi, a stark setting of T.S. Eliot’s well-known poem. This was the only piece in the programme with piano accompaniment, and I was pleasantly surprised when the introduction of the piano did not jar as much as I feared it would. This has much to do with Britten’s piano writing, which added a new expressive dimension in its autonomous wanderings. It was a highly powerful addition to the programme, Eliot’s strong poetic voice somehow amplified through Britten’s austere setting. The following carol, There is no Rose, sung by James and Jones, held an enchanting naivety that was thrown into sharper relief by the preceding work, and was both charming and moving in its simplicity.

Finally, all eight singers came together for Roger Marsh’s Poor Yorrick, the newest addition to the Ensemble’s repertoire. Taking its text from Laurence Sterne’s 1759 novel Tristram Shandy, the piece has a tripartite structure, in which the first section, which laments the passing of time with baleful, swooning oscillating chords over a staccato walking bass, recurs in the last, framing a central, recitative-style harmonisation of the prose text, which again switches between a few well-chosen chords. Despite its relative simplicity, Poor Yorrick is a highly effective, moving piece, with a twinkle-in-the-eye, and it was performed with the perfect blend of seriousness and melodrama. Whilst its bemoaning the swiftness of time’s relentlessness might seem a slightly strange note on which to end the festivities, the theme is probably breeched at most fortieth birthday parties – so why not voice those preoccupations beautifully?