The Oxford Concert Party describe themselves as "Europe's only Baroque and Tango Orchestra", which is ambitious enough, but, as a group of musicians who all work in the mainstream classical world, they are far more than this. Arne Richards and his multi-talented ensemble must be the only performers who, at an essentially classical concert, can get a stuffy, middle-class Oxford audience to sing Jingle Bells, not just once but three times, to encourage an eccentric Father Christmas to make an entrance, or to laugh uproariously at the appearance of a coy pantomime penguin who was given a series of edible gifts while the group played Claus-Dieter Ludwig's Happy Birthday Suite.

The secret behind the success of this hilarious overturning of the conventions of musical performance lies first with the ineffable mix of scholarly information and wickedly timed humour with which Arne Richards conducts the proceedings and, secondly, with the peerless musicianship of all the players.

Before the appearance of the penguin at the Holywell Music Room, the Oxford Concert Party had played a first half of baroque music with faultless precision and energy. The three Celtic pieces by Turlough O'Carolan and Joe Murray were delightful in themselves and played to get maximum understanding from lesser known compositions. The viola playing of Lisanne Melchior was particularly moving in Murray's The Coyles of Muick. Arne Richards's own composition The Cloths of Heaven, based on the poem of that name by Yeats was another example of Richards's ability to write searchingly emotional music and to perform on the accordion with the delicacy of a violinist.

The other side of the Oxford Concert Party, which makes them so effortlessly professional on the concert stage, is that much of their work is undertaken in the more challenging environment of prisons, detention centres and schools where they conduct extensive workshops to take the healing power of music to people on the edges of society - work for which they are sponsored by some of the most prestigious organisations in the country.

Oxford should count itself lucky that this ensemble has come back to its spiritual home after a period in the Lake District.