The Unusual Suspects are the best thing in Scottish music since the Celtic Connections festival itself.

It’s more of an idea than a regular line-up judging by the number of new faces on display at the festival’s closing weekend. But what a great idea it is — nothing less than a Celtic Big Band, adding a four-piece horn section, half a dozen fiddles, extra rhythm and percussion and other doublings to more conventional arrangements.

First and foremost, the sheer numbers do make for a joyful noise. But it is far more than that. This is an idea that people are currently trying to emulate all over the Celtic music world. A Breton outfit at the beginning of the festival had lots of people including a brass section but succeeded in being just as dull as before only louder.

The secret, apart from the tiny detail that all the players should be good enough to have bands or solo careers of their own, is in the arrangements and orchestrations, mainly by the pianist David Milligan and the harpist Corinna Hewat. The way they use the brass in particular, two trumpets, an alto sax and a trombone, is extremely sophisticated, much aided by Rick Taylor, the vastly experienced trombone player.

Using mostly existing tunes but drawing on lots of jazz influences, the brass is often a sustained choir while whoever is carrying the melody is chattering away. Together, they add colour, depth and the kind of variety that traditional music, with the best will in the world, sometimes lacks.

The band was cheered to the echo by a delirious crowd, partly because this was such a rare treat. We happily subsidise 80-piece symphony orchestras but, apart from some start-up money, no one at the funding bodies seems to grasp that a 22-piece band of any kind faces similar challenges. As a result the Unusual Suspects are not often rounded up.

However, the band is to headline the 50th anniversary celebrations of the European Union in Berlin next month, playing to an anticipated crowd of 25,000 at the Brandenburg Gate, which should raise their profile a notch.

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