Beneath the joy and celebration of the Christmas message there is a sobering, perhaps chilling set of truths and when top-notch musical artistes connect fully with these, you had better watch out.

When they do, the effect is of time standing still. It happened several times in this appearance by the Carnival Band and Prior, whose maturity, personality and experience on bands never allow herself to stand apart as the separate entity in which she is marketed.

Outstanding in this were two items. The band's own writing collaboration was responsible for one, incorporating 20th century poet John Short's line "Poor as a Salford child" in reference to Jesus' bleak and humble birth; the other was their now familiar North American traditional, a cappella (unaccompanied) Poor Little Jesus.

All instruments were silenced and four of the five instrumentalists, as if they were not talented enough already, unwrapped their additional talent for harmony singing. Poor Little Jesus haltingly started their encore, which ended in the rumbustious Bring Us In Good Ale, replete with sewn-in mediaeval dance tunes.

In another of their originals, A Latin Latin Christmas (rhythms and words) they hid four familiar carol melodies in the punchy "brass section" interjections of the shawms of Andy Watts and Giles Lewin, and offered an interval prize to the first of the audience to name all four. They were Jingle Bells, Silent Night, Deck The Halls and O Little Town of Bethlehem.

An inevitable highspot in their set is The Boar's Head Carol. This time the band, while Priory changed into a tangerine, multi-layered evening skirt, delivered it alone, straight after half-time and it hit us between the eyes, with Lewin - who plays violin, viola, Arabic Lute, and recorders, if you please - taking the lead voice.

Watts also brought to the feast as disparate instruments as a Turkish Clarinet (metal with a narrower bore) and a melodeon, a kind of electronic bagpipe. He had a genuine set ready for the Sussex carol.

Drummer Steve Banks had an economical kit capable of producing the necessary from anything between Susato-style European renaissance dance music, 1980s folk-rock and a 1920s palm court orchestra. He also played violin, often sweetly in tandem with Lewis, and he contributed another of their fine songs, Blue Pearl. This was inspired by the Apollo 8 space mission and the iconic, life-disturbing image of earthrise seen from the dark side of the moon: "Blue Pearl (I turn, I turn), One World (I learn, I learn)".

On highly agile string bass, fingered for jaunts, bowed for deep laments, was Jub Davis, and Steno Vitale played acoustic and Fender Strat guitars plus a mandolin he had plucked from a rubbish skip and re-strung. He contributed his own carol, Wake Up, which also exploited the blasting shawms.

Standard exhilarating fare for the Carnival is their traditonal and mediaeval carols in their own varied, seemingly spontaneous though highly organised treatments. The old German carol Joseph Dearest, Joseph Mine had five-part vocals and double violins. The lilting There Was A Boy had a plaintive tenor recorder counterpoint from Watts, and two sopraninos punctuated a Breton item, sung in French.

Shepherds Rejoice had them doing just that, to Lewis's jigging violin. And Personent Hodie had an elusive rhythm and was suitably raucous and rousing. Prior added her ironical anecdote that, as a schoolgirl who dropped out of Latin, she has ended up working with the language probably more than any of her classmates who stayed the course.

The quality and content of the Carnival Band's own writing contuinues to gain stature, their adventurousness less and less inhibited. Their Christmas single, Stuff, eyes the post-modern, commercial paraphanalia of Christmas in a muckabout approach and has co-opted Terry Jones of Monty Python's Flying Circus. It's out on December 17, from Park Records through Pinnacle.

They also have a new Album, Ringing The Changes on PRKCD98, to add to their several other now timeless Christmas catalogue (DVD In Concert PRKDVD87, Carols & Capers PRLCD9, and An Evening of Carols and Capers PRKCD87).

Gradually, this ensemble are establishing a way of marking and enjoying Christmas music for the generations keyed in to folk rock. It's different from your supposedly traditional Christmas offerings of candlelit carols, or choirs in decked halls. It's contemporary, yet just as authentic, and usually a lot less precious.

And with those pulse-stopping items up their sleeve, the Carnival Band can just as lethally stab your heart with the meaning of it all.