"The orchestra has been held up in traffic," apologises a gleefully nervous Kirsten O'Brien before a restless and rattling crowd of toddlers, teens and parents.

The conductor paces, shouting into his mobile phone before a discussion, perfectly scripted but seemingly spontaneous, sees the fragmented musicians find a way to fill the stage.

A solitary drum launches into Maurice Ravel's Boléro and, as fingers point, eyes stare and jaws drop, the players pour in carrying instrument cases, wearing motorcycle helmets, and looking realistically flustered. Each individual section slowly fills, adding to the swirling piece, until the final percussionist sprints in to bash a drum at its dramatic conclusion.

It's an awe-inspiring introduction and the children love it. From that point, everyone is whisked along with the varied programme, next stopping at Metal, an impressive, rhythmic piece by Graham Fitkin, sounding like Steve Reich enriched with a bit of fun courtesy of ships' bells and girders. Fitkin himself makes a surprise appearance, confidently describing the piece to the crowd.

Next are Leroy Anderson's The Waltzing Cat and Henry Mancini's The Pink Panther Theme, supported by meows and sound effects, before Watford violinist Emily Blogg takes to the stage to glide flawlessly through a solo on Jules Massenet's Méditation.

Other highlights include a Batman medley, Mambo from West Side Story and a samba version of Mozart's Rondo alla Turca.

Every piece is explained in a clear yet unpatronising manner and, though obviously aimed at children, the event is a near perfect attempt at classical music stripped of all pretence. Most leave the Colosseum pleased and inspired.

Filip Hnizdo