WHEN a choir as brilliant and ­ well-established as The Sixteen step on to the stage, it is evident we are witnessing experts at work.

Everything about this year's Christmas offering was flawless. The varied programme of Poulenc, Britten and medieval carols showcased the choir's exquisite sound, the type that draws you in, hanging on every beautifully placed syllable and warm tone.

Despite being only 20 singers, the choir filled the vast stage with clever staging, utilising every corner and at times venturing into the audience and up to the choir stalls. Harry Christopher's directing and programming continue to demonstrate how his enthusiasm for this music translates into enigmatic and unforgettable performances.

The Poulenc numbers were luxurious, with the austere, close harmonies controlled delicately by the choir. The opening set of four songs for male voices were sombre and prayerful, yet somehow brilliantly uplifting. The four Christmas motets were each given their own distinct character, with the soaring sopranos in the Magnum Mysterium, and the fluctuating harmonic movement in the second motet.

Interspersed through the Poulenc was a selection of medieval carols which were historically informed as a celebration of that period.

The songs were jubilant, and the rhythmic percussion accompaniment kept the music flowing where it could have lost momentum. Especially poignant was the lullaby for solo soprano, sung with a comforting and consoling simplicity. Britten's Ceremony of Carols was performed impeccably, capturing both the triumphant Christmas joy and the peaceful, spiritual contemplation that comes with it.

The most memorable piece was, of course, the Shepherd's Carol, which saw four singers serenading audience members, providing some light humour and comedy amidst a seriously sophisticated choral indulgence.