With BCMG, there’s never any concert so carefully planned, so meticulously and imaginatively put together, that it doesn’t allow room for spontaneity. This programme conducted by Oliver Knussen had already been adjusted to pay tribute to Knussen’s friend and mentor, the great American modernist Gunther Schuller: the evening opened with a playful, brightly-coloured account of Schuller’s Games.

But there were more surprises to come. Knussen was so taken with Hans Abrahamsen’s delicate, impressionistic arrangements of four Schoenberg piano miniatures that he repeated them on the spot. After the interval, he paused to dedicate the Group’s zingy performance of Stravinsky’s farmyard parable Renard to the memory of Stravinsky’s late collaborator Robert Craft, who died last week. Then, to finish, he threw in an entirely unexpected encore in the form of the same composer’s Ragtime. Well, the cimbalom was already on stage: it would have been a shame to miss the chance.

These things matter. BCMG has always placed its music in an evolving tradition. Not that there was anything of the museum about these performances: the audience laughed out loud as the four male singers of RSVP Voices strutted on stage to Renard’s raucous opening March. Earlier, Knussen had hurled great dayglow swirls of colour at Julian Anderson’s 2009 ballet The Comedy of Change; the players responded with flashing brilliance.

And they brought exactly the same commitment and precision to two new works. John Tattersdill’s plaintive bass solos framed the moody, blues-coloured arc of Melinda Maxwell’s premiere, Fractures: Monk Unpacked before the composer herself rose from the ensemble, oboe in hand, to take her bow. And Patrick Brennan’s scherzo Polly Roe managed in five shadowy, fleeting minutes to convince you that you’d heard something both wholly original and in its own way, perfect. Wonderfully unexpected.