Spitalfields Music honoured two composers with milestones in the closing concert of their Winter Festival at Christ Church on Tuesday. The first was Poulenc, who died 50 years ago, and the second the far more ubiquitous Britten.

The Sixteen began with just lower voices (they were to vary their formation frequently during the concert) for Poulenc’s Quatre petites prières de Saint François d’Assise. Written in 1948, after a nephew sent Poulenc the texts, they combine elements of plainsong and polyphony with 20th-century French harmonic colour. Harry Christophers brought a bright tone from The Sixteen, although in places the blend was a little top-heavy.

These were followed by three medieval carols, the highlight of which was Sweet was the song. A plaintive soprano solo accompanied by Frances Kelly on medieval harp, it had perfect ensemble and lovely ornamentation. Nowell, Nowell: Out of your sleep and Sing we to this merry company, on either side of it, would have benefitted from being a bit more raucously medieval.

We returned to Poulenc, and his setting of the Salve Regina, written in 1941. It maintains a largely homophonic four-part texture which creates a simple, devotional sound. This sound was beautifully brought out of The Sixteen by Christophers, with a real sense of pleading to the Virgin Mary.

After this we were back in medieval times, with three more carols. Of these, Angelus ad Virginem was the most polished, with a confident tenor solo. The soprano soloist was slightly overpowered by her male counterpart in Nowell, nowell: In Bethlehem, as was the medieval harp in Make we joy, but otherwise these were also fine performances.

The first half ended with the final Poulenc pieces of the evening, Quatre motets pour le temps de Noël. These were extremely moving, and highly expressive. The Sixteen truly invoked the mystery of O magnum mysterium and the shepherds in the fields in Quem vidistis pastore, which ended with a wonderful air of proclamation. Videntes stellam was truly beautiful, with a stellar clarity, and Hodie Christus natus est led us rousingly to the interval.

The second half was devoted to Britten, with just one medieval carol. It opened with the famous Hymn to the Virgin for choir and semi-chorus, written when the composer was still at school. Here, The Sixteen had opted to put the semi-chorus at the back of the church. This posed challenges for the ensemble in terms of timing and pitch, to which they rose admirably, creating a beautiful sound.

This was followed by the wonderfully humourous Shepherd’s Carol, setting words by W.H. Auden. The refrain is interspersed with solo verses, reflecting a much more personal experience of Christmas. Here, the soloists allowed themselves full enjoyment, popping up from the galleries or walking down the aisles. This was countered by beautiful, pure singing in the refrain.

After this came Britten’s arrangement of The Holly and The Ivy, with solo verses and ensemble refrain, and then The Salutation Carol, for lower voices. Throughout the concert The Sixteen’s admirable polish felt just a little too clean for these medieval carols, with more raucous energy needed.

The finale involved Opera North’s Children’s Chorus, supported by the upper voices of The Sixteen and Frances Kelly now on modern harp, in Britten’s Ceremony of Carols. It was lovely to see so many young singers of a very high quality; all performed from memory, mastering both the Middle English and Latin texts. The Procession came down the two sides of the church, with near-impeccable timing.

The young singers responded very well to Christophers, with Wolcum Yule confidently delivered. The choir reduced down to a semi-chorus of older members for There is No Rose. That youngë child was beautifully evocative, followed by a shimmering Balulalow. As dew in Aprille was strong, with the canon holding its shape well.

This Little Babe is perhaps the movement with the highest potential to go awry, but the youngsters had clearly been well-drilled, and the triple canon didn’t falter. We were then calmed with Frances Kelly’s stilling Interlude, before the semi-chorus evoked the nativity beautifully in In Freezing Winter Night, backed with Kelly’s trembling harp; while the Spring Carol was full of potent rebirth.

All voices came together for the Deo Gracias, alternating between strong proclamations and quietly energetic storytelling. The Recession again maintained near-impeccable timing as the youngsters left the stage, to be greeted by the applause of deservedly proud parents.

Not to be outdone, The Sixteen returned complete to encore us with the famous Gaudete. Here, at last, they let go and sang with energetic medieval enjoyment, creating a wonderful Christmas spirit. A fine end to a fine festival; here’s to next year!